Energy from the wind – the example of Wolfe Island Wind Farm, Ontario

by David Laing

We were shivering; bracing against a blustery, bone-chilling north-west wind, yet virtually hypnotized by the majestic beauty of the guardian towers and the gentle swish, swish, swish of the rotating blades. We wanted to linger far longer, but the cold won out as a freshening gust drove us back to the comfort of our car. It was a damp chilly day in early December 2012 and my wife Dayle and I were on Wolfe Island near Kingston Ontario, just finishing a visit to Canada’s second largest wind farm project. Our purpose was to get a firsthand perspective on the benefits and detractions of wind turbines as an economical power source for the Province of Ontario and also to understand the impact of those turbines, both positive and negative, on the local Wolfe Island community.

The Wind Farm on Wolfe Island boasts 86 turbines, each capable of generating 2.3 Megawatts, when running at peak capacity. The 197.8 megawatt farm is just under the 200 megawatt limit allowed in Ontario. Of course theoretical capacity is not the same as actual output. The wind is fickle and the turbines aren’t always spinning at their maximum velocity. Maintenance activity, both scheduled and unscheduled also reduces wind farm capacity. But, even considering these inefficiencies, Wolfe Island produces sufficient electricity to meet over 68% of the power requirements for the Kingston Metropolitan Area. [1]

TransAlta completed construction of the facility in 2009 and is committed to a 20 year contract to produce wind-based power for Ontario’s Power Authority. At something less than 9.2 cents a kilowatt hour, (exact contract terms are confidential), the price compares favourably to nuclear and hydro when all the cost for construction, maintenance, operations and environmental impact are taken into consideration.[2]

Proposing to build an industrial facility in a natural setting is a certain recipe for controversy and Wolfe Island was no exception. According to our long-term friends, who moved to the island well before the wind farm project was conceived, the prospect of dozens of 80 metre towers rising above relatively flat agricultural land that also is part of a major bird migration route, elicited a particularly strong negative response from many local residents. The controversy initially divided the community, pitting family members against each other, prompting at least one to pack up and move away.

Yet 3 ½ years after TransAlta Corporation completed construction and began operations, our friends have indicated that the majority of the residents think that the wind farm is more of a benefit than a detraction to the island and that TransAlta is a pretty good neighbour, as corporations go. To discover more, we asked our friends to contact their neighbour Mike Jablonicky who also happens to be Wolfe Island’s Wind Farm Supervisor of Operations.   And so a visit was arranged for that frigid December morning.

Friendly and approachable, Mike is clearly enthusiastic about his job and very proud of the farm and its operating team. We learned that he was assigned to the project from the beginning. He was, and still is the communications point person, handling all manner of objections and complaints from the local residents.

When asked about the acceptance rates for the project prior to construction, Mike smiles and hands us the “fact sheet” published by a group who were, at the time, anxious to stop the project. “Reading that, he said, I would be scared to the point that I wouldn’t want a wind-farm in my area as well”. The early objections he said mostly came down to myths, misunderstanding and a lack of information. For instance, residents were told that, during storms, ice could collect on the turbines and be thrown hundreds of metres by the spinning blades in chunks the size of a bus. Or that the vibration of the towers would crush turtle eggs, kill the crops because the dew worms would leave the area and cause cows to lose their minds and stop calving.

Mike hosted monthly communications sessions, talked to people in small groups and even one-on-one. Each issue was addressed in turn. He demonstrated the mechanics of how any ice build-up on the turbine blades would cause the turbine to slow down and stop, not throw ice off. He explained how vibration, significant enough to damage turtle eggs, would, in fact, destroy a turbine tower in about 3 hours of operation. As a result, he said the three turbine blades, each weighing about 11 tons, is balanced to within 20 pounds of the other two such that tower vibration is virtually eliminated. He also showed concerned residents pictures of other wind farms where crops grow and cattle graze right up to the tower base. Once the farm was in operation, these fears were proven to be unfounded which added to Mike’s credibility and helped build trust between TransAlta and the community. Support for the wind farm development crept above 50% for the first time since the project was announced.

But some issues aren’t myths. Wind farm detractors point to thousands of bird and bat deaths each year from interactions with the turbine blades. Complaints arise from turbine noise, both audible noise and low frequency “infrasound”, which is thought to be a cause of negative health effects such as: sleep disorders, headaches, depression and changes to blood pressure[3]. Then there is the undisputable fact that wind farms forever alter the skyline. Handling these real objections required more than talk and education. Mike, and the company, had to have a process and an action plan for mitigation.

To mitigate bird and bat kills, TransAlta worked with the University of Calgary’s Professor of Biology Robert Barclay, to carry out a number of independent studies. The research indicated bat deaths were the far greater problem and the highest concentration of bat deaths occurred at low wind velocities.[4] This lead TransAlta to adjust its procedures around wind farm operations in low wind conditions with the effect that bat fatalities have been reduced by 60%.[5]

The latest available data from the Wolfe Island studies estimates about 900 birds and 1,900 bats were killed at the facility in 2011. This number is considerably below the Adaptive Management Threshold as set by Environment Canada.[6]

While the hundreds of thousands of wildlife deaths caused by wind turbines in North America are of concern, it is important to put this in perspective when compared to the billions of bird and bat deaths caused each year in collisions with high-rise buildings and attacks by domestic housecats. [7]^,[8],[9]

In terms of ambient noise, Ontario regulates turbine set-backs from any private residence such that the noise at the residence must not exceed 40 decibels. Mike brought in a decibel meter and showed residents that 40 decibels is about the level of a quiet library conversation. He told them anything above that meant something very likely was wrong. He posted his cell phone number and told residents to call him with noise issues “twenty-four seven” and that “he would be there in 15 minutes”. When tested, even at 2:30 in the morning, Mike was responsive, coming out to check on the problem and shutting down the offending turbines until repairs were made. More trust and credibility accrued to Mike and approval levels continued to rise.

The health effects of low-frequency noise present a more difficult challenge. According to Mike, studies by local and provincial authorities along with the World Health Organization have so far, not been able to correlate either low or high frequency noise with any deleterious health impacts. The collective conclusion is that, for some people, living near a wind farm is such an emotional irritant that the annoyance factor alone may be the cause of negative health effects. So this issue remains unresolved although Health Canada is now sponsoring a very comprehensive study. The results are expected in late 2014 and it is hoped this will allow more definitive conclusions to be drawn.[10]

Then there is the issue of wind farm aesthetics. Mike and TransAlta recognized that wind turbines do alter the landscape and this may be disturbing to some people. They addressed this issue non-defensively, in effect offering financial compensation in return for loss of view. During construction, over 400 on-site construction jobs and purchasing through local companies injected $22M over 11 ½ months into the local economy. After construction was completed TranAlta continues to frequent local stores for hardware, gas and automotive repairs. Several permanent well-paying jobs were created and filled with local labour. In addition, each year TransAlta provides the community with “amenities money”: $634,000 to be used for the betterment of the community such as road construction, beach-bike paths and a new water system. As a result, everyone on the island benefits from the presence of the wind farm whether or not they have a turbine on their property.

So after 3 ½ years of operation, Mike says, “I think we are about a healthy 80-85% acceptance rate, [by the residents], right now and, that’s probably as far as we’re going to get, and that’s Ok. We can’t have 100% consensus on anything we do in any community…80-85%, I’ll take that.”

I’ll admit to bringing a certain bias to this investigation. Dayle and I have stood beneath modern wind farms in several locales around the world: Costa Rica, Hawaii, Europe, Britain, South Africa and North America. In each case we have been impressed by the elegance of their functional design.

We all must recognize that there is no method of producing electricity that is 100% benign. While there is no mistaking their industrial application, wind farms are less disruptive and integrate far better into the natural surroundings than other power producing alternatives. Aesthetics aside, for us there is an unmistakeable appeal in their ability to generate much needed electrical power, using wind as a “free fuel” that is non-toxic, produces no carbon emissions and that will be available for as long as the sun continues to shine on our planet.

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[1] 2011 Power consumption statistics courtesy of Ontario Energy Board http://www.ontarioenergyboard.ca/OEB/

[2] “Facts and Myths debunked – Facts and Figures Ontario’s Electricity System”, Ontario Citizens Coalition for Clean Affordable Energy, http://www.occcae.org/facts-and-myths-debunked.php

[3] “Health Canada lays out a plan for study of wind farms, Globe and Mail, February 11, 2013, pg. A3

[4] Bat deaths from wind turbines explained, University of Calgary, Aug 2008. http://www.ucalgary.ca/news/aug2008/batdeaths

Exploring neighbourhood energy futures

Northern Gateway pipeline is more than just an environmental issue

By Bob Worcester

The Northern Gateway Pipeline is pitting U.S. interests against the Chinese, and Alberta against B.C. Five oil sands companies have revealed themselves as supporters of the controversial Northern Gateway pipeline, lending their names to a massive infrastructure proposal that has stirred intense opposition in Western Canada. Cenovus Energy Inc., MEG Energy Corp., Nexen Inc., Suncor Energy Marketing Inc. (a subsidiary of Suncor Energy Inc.),and Total E&P Canada (the domestic arm of French giant Total SA) have each spent money to help develop the $6.6-billion pipeline which, if built, will funnel massive volumes of oil sands crude to the West Coast for export to California and Asia. Gateway’s financial backers also include Chinese state-owned energy company Sinopec. And there are others who have yet to step forward. Market sources have said they believe China National Petroleum Corp. also holds an interest in Gateway. Sinochem Group, another Chinese energy firm, is also believed to support Gateway.

Against this backdrop a story is emerging that Canadian environmental groups receive some funding from US charities. Canada’s Conservative government is using this as a “talking point” against the swelling opposition to the Gateway pipeline and tar sand development. The government seems to be taking a very narrow view as to what constitutes the “national interest.”

No one can deny that billions of dollars of foreign investment will impact the Canadian economy. It seems easier, however, for the government to deny that billions more tonnes of greenhouse gases will impact the Canadian (and global) climate. Despite the petro-dollar funded denials it remains an “inconvenient truth” that we are mortgaging the health and welfare of our children and grandchildren in the rush to exploit the last remaining fossil fuel deposits and get them to market across BC’s pristine northern forests and rivers.

Oil and gas geologists know very well what global warming is doing to arctic ice and northern tundra. They drive through the infestation of warm weather pine beetles in BC’s boreal forests. For them it is merely the cost of doing business, knowing that they are not even being asked to pay those costs. Those costs are being passed on to our children in the form of catastrophic climate changes now occurring faster than the IPCC’s worst predictions.

Environmentalists are raising the alarm because the facts are truly alarming. This is much more than merely an environmental or economic issue. It is an eldership issue of survival. Elders have understood for generations the dangers of reckless exploitation and resource exhaustion. Those cultures that heed the warnings survive and thrive while those that don’t disappear into the mists of history. The difference now is that the impacts are global and there are no more uncharted territories to shelter the survivors.

Ecology has no national interest. Iroquois Law is often described as decreeing that decisions must consider seven generations. Sadly, governments are bound instead to election cycles and oil companies are bound to balance sheets and annual reports. Eldership transcends those limitations and never was there a greater need for elders to be heard. Canada’s national interest is a sustainable future for its next generation. Who will speak for them?

COP 17 – Spotlight on Adaptation Negotiations

by Rachel Berger

Durban Outcomes

The most important thing out of Durban to understand is that we have not yet succeeded in moving the world away from a dangerous trajectory towards well above two degrees of global warming.

In Durban, the political space has been kept alive for further negotiations, but without political will leading to a big increase in mitigation action from developed countries, and investment to support such action in the larger developing countries, global temperatures will continue to rise, moving the world from increasingly frequent extreme climatic events towards tipping points and catastrophe.

The period between now and 2020 is a crucial time for action. To raise our chances of stabilising the climate (i.e. preventing a temperature rise of more than 2°C), climate science indicates that 2020 is the latest date by which emissions must have peaked and begun to decline. A legally binding agreement requiring emissions cuts from all countries before 2020 is doubtful, and thus a disaster waiting to unfold.

An increase in global temperatures of 4°C is potentially a death sentence for many countries in Africa, many Small Island States, and the poor and vulnerable worldwide.

Adaptation Negotiations

The negotiations on adaptation were aimed at following up the agreement in Cancun last year to establish the Adaptation Framework. Agreement was reached in Durban on four elements of this:

1. Guidance on the Preparation of National Adaptation Plans (NAPs) was agreed. This is for least developed countries and other developing countries who wish. NAPs were agreed to be country driven, participatory and gender‐sensitive, and fit in with other national planning and development strategies, hence the guidance is not prescriptive. The agreement last year indicated that funding would be provided to meet the cost of plan preparation, and later, implementation. In Durban, all that was agreed was that an existing fund, the Least Developed countries Fund, may now also support National Adaptation Plans. This fund was established to support an earlier set of plans for least developed countries (National Adaptation Programmes of Action, (NAPAs)), which were actually defined as short term projects.

The main problems with this are that this fund, managed by the GEF, has been very slow to disburse funds to countries, and developed countries are requested to support NAP preparation, either in bilateral arrangements or through making contributions to the LDC Fund. Until long term finance is agreed, and flowing into the Green Climate Fund, the outlook for adequate support for adaptation is bleak.

2. Establishment of an Adaptation Committee was agreed. The Adaptation Committee will be the overall advisory body to the COP that will oversee all of the different adaptation activities under the UNFCCC. Its remit will be to ensure effective sharing of information on good practice in adaptation and coordination between the various regional and UN bodies that work on adaptation, as well as with other centres and networks. The Committee will have scope to organise workshops, commission reports, and establish expert groups, to assist in its work.

The Committee’s composition has been agreed, and will have a developing country majority, and while governments nominate the members, they are encouraged to nominate people with relevant expertise. The committee is encouraged to involve civil society and other relevant bodies in its work, and the meetings will be open to observers. The work programme for the first three years of the committee is to be drawn up during 2012 for approval by COP 18.

3. Agreement was reached on Loss and Damage due to Climate Change. This is related to the impacts of extreme weather events and slow onset events, and how to manage the risk associated with them. A work programme during 2012 will hold workshops and prepare reports for consideration at COP 18. This agreement was a stronger outcome than we expected.

4. Agreement on two further years of knowledge sharing and capacity building programme on understanding the impacts of climate change, and adaptation. There will be workshops on water, climate impacts and adaptation, and on ecosystem‐based adaptation. Support will be developed on national adaptation planning. The two year programme is to be undertaken with close involvement of partner organisations, who are invited to share their ideas for further activities within the programme, and to offer support to meet the needs of governments.

Technology & Adaptation

Decisions on technology were linked with decisions on adaptation, since access to knowledge and technologies is vital for enabling adaptation. This led to the establishment of the Technology Executive Committee, and the Climate Technology Centre and Network (CTCN). Key roles of the CTCN include:

• Identifying currently available climate friendly technologies for mitigation and adaptation that meet their key low‐carbon and climate‐resilient development needs; and
• Facilitating adaptation and the deployment of currently available technologies to meet local needs and circumstances. An open tender process will be invited for hosting the Climate Technology Centre in 2012.

The Road Ahead

All of these fairly positive decisions have to be seen against the backdrop of postponement of strong and binding emissions targets on developed countries, and a lack of commitment on finance after the end of 2012. In this context, adaptation will become extremely difficult for many communities, and poorer countries will struggle to develop and implement programmes to help protect their people.

Rachel Berger is the Practical Action Climate Change Policy Advisor, DEW Point Development Resource Centre, United Kingdom. The news item has been reproduced with the kind permission of DEW Point.

The pros and cons of nuclear power versus coal

by Peggy Olive

In an ideal world, inexpensive, reliable, and safe sources of green energy would abound, and we could avoid using energy derived from either nuclear fission or coal burning. But we’re not there yet, and with climate change already affecting life on our planet, most of us believe that we need to move quickly to using clean energy sources to limit the rise in global temperature caused by greenhouse gas emissions.

In a talk on energy and climate entitled, “Innovating to Zero”, Microsoft’s Bill Gates gives a compelling argument for why we need nuclear power in an age of increasing levels of atmospheric CO₂ [1]. Using a simple equation, he argues that CO₂ is a product of the number of people on the planet, the services delivered per person, the energy needed per service, and the amount of CO₂ produced by each unit of energy. The first two are heading up and are unlikely to be stopped. The cost of energy is decreasing, but not enough. So that leaves the fourth factor. We must use energy that does not produce greenhouse gases, but we need reliable energy – energy that’s available when the sun doesn’t shine and the wind doesn’t blow. Gates believes that nuclear power offers this promise and should be part of the mix, especially if improved (safer) technology is employed. Energy conservation should be a viable way to transition from dirty to clean energy, but increases in services delivered per person along with a growing population would quickly eat up conservation savings.

Like coal power, nuclear power is economical and does not fluctuate as much as wind or solar power. Unlike coal, it is considered clean in terms of the amount of greenhouse gas emissions produced by the power plant itself, although uranium mining and processing are not without risks and environmental impact. But the public is overly fearful of nuclear power, seeing it as an accident waiting to happen and, when it does, likely to adversely affect millions. Of equal concern, radioactive wastes from power plants accumulate and represent a threat by terrorists willing to handle the material, but this has not yet occurred. Accidents at nuclear power plants have the potential to be dangerous to the local population and environment as we’ve recently appreciated with the Fukushima disaster, and once long-lived radioactive elements like cesium-137 and strontium-90 are released, they can contaminate the surrounding land for decades. A case in point, the a 30 km exclusion zone surrounding Chernobyl remains empty of people twenty-five years after that disaster.

Fortunately, nuclear power plant “accidents” that spread deadly isotopes are rare, and the planet has suffered only two (avoidable) serious events that rank at the top of the International Nuclear Event Scale. As serious as these events were, there were few immediate deaths. At Chernobyl, the nuclear core of a poorly designed and operated reactor exploded and was cast outside the facility. Thirty-two radiation workers died shortly after radiation exposure at Chernobyl. At Fukushima Daiichi, in spite of IAEA concerns, an older reactor was operating without adequate safety precautions to ensure reactor coolant in the event of an earthquake and tsunami. No one has died from acute radiation poisoning at Fukushima. Other than thyroid cancers (which are mitigated by potassium iodide tablets and easily treated) increases in the incidence of other types of cancer have not been conclusively linked to radiation from the Chernobyl accident [2]. Cardis and colleagues [3] estimated that “of all the cancer cases expected to occur in Europe between 1986 and 2065, around 0.01% may be related to radiation from the Chernobyl accident”. Although a tiny percentage, this still represents a large number of excess cancer cases, more than 5000 to date. However, air pollution is estimated to end life prematurely in at least 17,000 US citizens per year [4] and up to 850,000 globally [5]. A 2002 analysis by the International Energy Association concluded that nuclear power ranked much lower than coal in terms of impact on biodiversity, accidents, and health risks, and only ranked higher on risk perception [6].

When seen in comparison to the risks of deriving energy from burning coal, the evidence that deriving energy from nuclear power is dangerous remains relatively weak. It is the perceived threat that is strong, and this threat recently caused Germany to close eight of their nuclear power plants and to begin to phase out the remaining nine by 2022. Although the intent is to generate energy cleanly, almost half of the energy in Germany currently comes from coal, and it is difficult to believe that this percentage will not rise in the next few decades, thus contributing further to global warming.

Coal-derived power, in addition to being a major contributor to greenhouse gas emissions and acid rain, is hardly safe. Thousands of coal miners die in accidents each year, and the public is susceptible to lung and heart effects from air-borne pollutants. In 2000, the Ontario Medical Association declared air pollution “a public health crisis” [7] and coal-fired power plants as the single largest industrial contributors to this crisis, producing carbon dioxide, fine particulates, and cancerous heavy metals including mercury. In 2005, the Ontario Medical Association estimated that air pollution costs the province more than six hundred million dollars per year in health care costs, as well as causing the premature deaths of thousands of Ontarians each year [8]. Although of little health consequence, it is worth noting that burning coal produces fly ash that concentrates natural radioactive isotopes in excess of levels produced by nuclear power plants under normal operating conditions [9]. Disposal of toxic coal combustion wastes, orders of magnitude larger in volume than nuclear wastes, has also come under scrutiny [10].

We constantly accept risks in our lives without giving it much thought. A person who smokes twenty cigarettes a day over their lifetime would shorten their life, on average, by six years. A person currently living 50 km from Fukushima who is exposed to an extra 3 mSv per year over their lifetime (the average background exposure is now greater than 3 mSv per year thanks to medical imaging) would shorten their life by 15 days [11]. What cannot be easily evaluated, and is therefore ignored in these risk assessments, is the psychological trauma to evacuees and to those who fear the consequences of minimal radiation exposure because they do not comprehend the risks. Wild animals, ignorant of continuing radioactive decay, are now thriving in the Chernobyl exclusion zone [12].

Economic arguments favour the use of coal over nuclear power when waste management and decommissioning are taken into account. Nuclear plants are very expensive to build (and dismantle) although estimated capital costs for advanced coal plants with carbon control and sequestration appear to be on par with costs to build nuclear power plants [13]. The cost to run and maintain coal plants can be higher than nuclear power plants, in part because of the transportation costs of coal. A major concern with both nuclear and coal power plants is that once the plants are built, they are likely to be around for a long time because the infrastructure is so costly to develop. Public pressure will be needed to ensure that these plants are closed as soon as clean energy sources become available.

In summary, although recent events at Fukushima warn us that safety standards and compliance must be improved, nuclear power plants operating normally produce less greenhouse gas and toxic emissions, less global environmental damage, and fewer health issues than coal-burning power plants. Neither represents a safe, sustainable, energy choice, but given a choice between these two, nuclear power comes out on top. According to Walter Keyes, a proponent of nuclear power who has worked as an energy consultant for the Saskatchewan and Federal governments, “If climate change really is the serious global issue that most scientists believe it is, there is a very limited amount of time to fix the problem and we should not be wasting valuable time debating which non GHG (green house gas) generation source is the best – we need them all, desperately!” [14].

References

1. Bill Gates on Energy: Innovating to Zero! TED talks, February, 2010. http://www.ted.com/talks/bill_gates.html

2. UN Summary of the Chernobyl Forum, Chernobyl’s Legacy: Health, Environmental and Socio-Economic Impacts, IAEA, 2006. http://www.iaea.org/Publications/Booklets/Chernobyl/chernobyl.pdf

3. Cardis E, Krewski D, Boniol M, Drozdovitch V, Darby SC, Gilbert ES, et al. 2006. Estimates of the cancer burden in Europe from radioactive fallout from the Chernobyl accident Inter. J Cancer 119, 1224–1235 (2006).

4. US Environmental Protection Agency, Power plant, mercury and air toxics standards, March, 2011. http://www.epa.gov/airquality/powerplanttoxics/pdfs/overviewfactsheet.pdf

5. World Health Organization. Estimated deaths and DALYs linked to environmental risk factors. http://www.who.int/quantifying_ehimpacts/countryprofilesebd.xls

6. International Energy Agency, Environmental and health impacts of electricity generation, June 2002 (Table 9.9) http://www.ieahydro.org/reports/ST3-020613b.pdf

7. Canadian Medical Association, June 27, 2000. http://www.collectionscanada.gc.ca/eppp-archive/100/201/300/cdn_medical_association/cmaj/cmaj_today/2000/06_27.htm

8. Ontario Medical Association Illness Costs of Air Pollution (ICAP) – Regional Data for 2005. https://www.oma.org/Resources/Documents/d2005IllnessCostsOfAirPollution.pdf

9. McBride JP, Moore RE, Witherspoon JP, Blanco, RE. Radiological impact of airborne effluents of coal and nuclear plants. Science, 202: 1045-1050, 1978.

10. Dellantonio A, Fitz WJ, Repmann F, Wenzel WW. Disposal of coal combustion residues in terrestrial systems: contamination and risk management. J Environ Qual. 39:761-75, 2010

11. U.S. Nuclear Regulatory Commission, Instruction concerning risks from occupational radiation exposure. Regulatory Guide 8.29, Feb. 1996. http://www.nrc.gov/reading-rm/doc-collections/reg-guides/occupational-health/rg/8-29/08-029.pdf

12. Hinton TG, Alexakhim R, Balonov, M., Gentner N, Hendry J, Prister B, Strand P, Woodhead D. Radiation-induced effects on plants and animals: Finds of the United Nations Chernobyl Forum. Health Physics 93: 427-440, 2007.

13. US Department of Energy/Energy Information Administration, Levelized cost of new generation resources in the annual energy outlook 2011. http://www.eia.gov/oiaf/aeo/electricity_generation.html

14. Howell, G and Keyes W, Green (renewable) energy versus nuclear energy. Part five of an eight part written debate regarding nuclear power generation. Mile Zero News and Banner Post, March 17, 2010. http://www.computare.org/Support%20documents/Guests/MZN%20Nuclear%20Debate/5%20of%208%20Green%20Energy%20Howell-Keyes.pdf

Are conservatives just naturally anti-environment?

by Stan Hirst

Just one month ago the federal general elections in Canada put the Conservative Party firmly in power. Responses to the election outcome amongst environmental groups and environmentally-concerned individuals across the country ranged from disappointment to dismay to a number of other reactions, most of them negative.

The reason is not hard to discern. Conservatives in Canada are perceived as having an awful environmental track record. For the recent election, the Conservative Party‘s election platform contained not one word about environment. By contrast, the opposition Liberal Party promised to create clean energy jobs, invest in clean energy and energy efficiency, create a cap-and-trade system for reductions in greenhouse gas emissions, and to protect Canada’s air, oceans, waterways, forests and Arctic resources. The New Democratic Party’s platform proposed a shift away from fossil-fuel dependence, underlined the compatibility of environmental health and economic growth, and promised to develop green energy industries.

The future doesn’t seem to bode much better. The background documents for the June 2011 Conservative National Convention, at which future policy was set, contained just one short statement on an environmental topic, i.e. “we believe that an effective international emissions reduction regime on climate change must be truly global and must include binding targets for all the world’s major emitters, including China and the United States”.

Is this disconnect between conservatism and environmental consciousness in Canada typical of all conservatives or conservative governments? Consider the following statements from south of the 49^th parallel.

1. I do not intend that our natural resources should be exploited by the few against the interests of the many.
2. The only trouble with capitalism is capitalists – they are too damn greedy.
3. As we peer into society’s future, we – you and I, and our government – must avoid the impulse to live only for today, plundering for, for our own ease and convenience, the precious resources of tomorrow. We cannot mortgage the material assets of our grandchildren without risking the loss also of their political and spiritual heritage.
4. The basic causes of our environmental troubles are complex and deeply embedded. They include: our past tendency to emphasize quantitative growth at the expense of qualitative growth; the failure of our economy to provide full accounting for the social costs of environmental pollution; the failure to take environmental factors into account as a normal and necessary part of our planning and decision making; the inadequacy of our institutions for dealing with problems that cut across traditional political boundaries; our dependence on conveniences, without regard for their impact on the environment; and more fundamentally, our failure to perceive the environment as a totality and to understand and to recognize the fundamental interdependence of all its parts, including man himself.
5. We are now facing hard choices in our energy policy. Future generations — my children and grandchildren, along with yours — will have to live with the decisions we make today. And so it is time for us to make some tough and — hopefully — smart choices regarding our energy use and production before it is too late.

All penned and uttered by democrats and green-tinged radicals, right? Wrong. All spoken by hard-core Republican conservatives – Theodore Roosevelt, Herbert Hoover, Dwight Eisenhower, Richard Nixon and John McCain.

Or maybe the disconnect between conservatism and environmental consciousness in Canada now typifies the attitudes of mainstem right-wing parties struggling to deal with 21^st century environments? A quick check around the globe suggests that this isn’t true either.

The British Tories, the party of Disraeli, Churchill and Thatcher, are today in a coalition with the Liberal Democrats. The Conservative 2011 programme declares that Britain needs to protect the environment for future generations, make the economy more environmentally sustainable, and that much more needs to be done to support the farming industry, protect biodiversity and encourage sustainable food production.

The governing German party, the Christian Democratic Union, declares in its manifesto that its policies are based on the Christian view of Man and his responsibility before God, and then goes on to state that the objective of an ecological and social market economy, as they see it, is to achieve a synthesis of economy, social justice and ecology. Amongst a host of economic and policy actions cited as a basis for this synthesis, the CDU include the need for ecological elements in tax legislation, environmental levies, compensation schemes, certification and liability regulations, and the cutting edge concept, at least by current Canadian standards, of rewarding environmentally sensitive actions by using market incentives and linking costs to environmental damage to establish ecologically realistic prices.

Flipping to the other side of the globe, we find the most conservative party in Australia, the rural-based National Party of Australia, outlining its 2011 environmental platform by supporting targets for greenhouse gas emissions, proposing direct action plans to reduce emissions through soil carbon sequestration and use of bio-char, revegetation of marginal land, clean coal technology, carbon capture and the use of algae, and encouraging public participation in voluntary carbon markets involving individuals, communities, agriculture and business, and strong state support to non-petroleum based fuels. Pretty radical stuff all around.

So why are Canadian conservatives not up there with the rest of the conservative world in addressing urgent environmental issues?

Conservatives believe in personal responsibility, limited government, free markets, individual liberty, traditional values and a strong national defence. Thus, conservative policies generally emphasize empowerment of the individual to solve problems. By contrast, those of more liberal persuasion believe in government action to achieve equal opportunity, equality for all, alleviation of social ills and the protection of civil liberties and individual and human rights. So liberal policies generally emphasize the need for the government to solve problems.

Looking at energy through this type of filter, we might see that Canadian conservatives consider fossil fuels to be good sources of energy (which they are of course in Canada) and, since they are abundant, their exploitation should be promoted and increased both on land and at sea. Increased domestic production by large corporations would lead to lower domestic prices plus huge incomes from the two biggest gulpers of energy on the planet – the U.S. to our south and the ever-burgeoning Chinese economy just across the Pacific. Canadian conservatives might feel that wind, solar and biomass will never provide comparable levels of plentiful, affordable and, above all, profitable sources of power. The opposing liberal view points, i.e. that oil is a diminishing resource, that other sources of energy must be explored, that government must produce a national plan for all energy resources, and must subsidize alternative energy research and production don’t play well in Canada because fossil fuels generally are not diminishing resources. They may be getting more difficult and expensive to recover, but that is just part of the ongoing and traditional challenge for private enterprise.

Looking at climate change through the same filter would surely lead a market-conscious conservative to conclude that since global warming is caused primarily by an increased production of carbon dioxide through the burning of fossil fuels, which Canada produces, and burns, in prolific quantities, the combating of climate change needs to involve realistic pricing of fossil fuel extraction and use through carbon taxation and firm regulation, through reduction in fossil fuel use by a plethora of measures to increase energy supply from renewable sources, and by a shift in consciousness towards regarding earth as an ecosystem, and not as a supply depot. All of this is missing from the current conservative platform, who sees it all as just raising taxes, increasing prices, losing jobs and impacting on individual freedoms. A prevalent conservative approach to dealing with climate change is to deny that it is happening at all.

Climate change presents a very difficult problem for Canadian conservatives. The root cause of the problem is burgeoning greenhouse gas emissions from fossil fuel use around the globe. Once upon a time the major contributors of greenhouse gases to the global climate were North America and western Europe. Now they’re increasingly being put out by the Asian industrial powers, and Canada contributes to their impacts by selling them oil and coal. And while the causes of climate change are global, the impacts – storms, droughts, rising sea levels, disappearing glaciers, changing weather patterns – will be felt globally as well. The items in the classic conservative toolkit – personal responsibility, limited government, free markets, individual liberty, traditional values and empowerment of the individual to solve problems – have not thus far dealt well with the root causes of climate change. Maybe they’ll deal better with the consequences.

We’re doomed

The following post contains material of a depressing nature, and is unsuitable for readers under 65 years of age. Reader discretion is advised.

First point – the global climate is changing. Not many people dispute that any more. The mean global temperature has risen by 0.8°C over the past century, and the ten warmest years on record have all occurred since 1998. Within the past century many significant climate changes have been measured and reported, including increases in the frequency of heat waves in the U.S., an increasing proportion of precipitation coming in the form of intense, flood-inducing events, an increase in tropical cyclone intensity in the Atlantic Ocean, Caribbean, and Gulf of Mexico, a huge decrease in the seasonal extent of Arctic sea ice, and a big jump in the rate at which glaciers are melting.

The rates of change seem to be accelerating and most of the profound secondary changes are negative. Dr James Hansen, the NASA scientist who first drew international attention to the impending climate disaster, testified way back in 1988 that Earth had entered a long-term warming trend. Today the effects of global warming on the extremes of the global water cycle – stronger droughts and forest fires on the one hand, and heavier rains and floods on the other – have become more evident in Australia, Europe, North America, Africa and Asia.

Second point – the causal factors of climate change are now very well known. Earth is surrounded by a relatively thin layer of greenhouse gases – water vapour, carbon dioxide (CO2), methane and nitrous oxide – which act as a thermal blanket. About half the incoming solar radiation passes through the atmosphere to the Earth’s surface where some is absorbed and the remainder reflected back into the atmosphere. Substantial amounts of the energy absorbed are again radiated outward in the form of infrared heat. These contribute further to the warming of the atmosphere.

Third point – humanity has drastically changed global climatic dynamics by adding huge amounts of CO2, methane, nitrous oxide and chlorofluorocarbons to the atmosphere. Activities such as deforestation, land use changes and the burning of fossil fuels have increased atmospheric CO2 by a third since the Industrial Revolution began. Decomposition of wastes in landfills, burgeoning agriculture, especially rice cultivation, and huge populations of burping and manure-producing domestic livestock have boosted the amounts of methane in the atmosphere by a factor of three since the industrial revolution. Methane is twenty times more active than CO2 in atmospheric heat retention.

The atmospheric concentration of CO2 measured at the Mauna Loa Observatory in Hawaii is a good indicator of where we are now globally in respect of atmospheric change. Back in 1959 when the data collection programme was initiated by the National Oceanic and Atmospheric Administration (NOAA) the CO2 level was measured at 316 parts per million (ppm) and the annual increase was less than 1 ppm. Today the level is over 392 ppm and the annual increases are 2.2 ppm and getting larger all the time.

James Hansen and his climate scientist colleagues concluded that we have either reached, or are very close to, a set of climate “tipping points”. That means that climatic changes are now at a point where the feedbacks from changes spur even larger and more rapid further changes. Hansen cites Arctic sea ice as a good example of this. Global warming has initiated faster sea ice melt and has exposed darker ocean surfaces that absorb more sunlight which leads to more melting of ice. As a result, and without any additional greenhouse gases, the Arctic could soon be ice-free in the summer. The western Antarctic and Greenland ice sheets are vulnerable to even small additional warming – once disintegration gets well under way it will become unstoppable.

Pause for reality check – not only is climatic change a reality, it is progressing at an accelerating rate, the negative consequence are getting greater, and the likelihood of us managing to slow or reverse the negative trends are getting smaller.

Fourth point – James Hansen and his fellow climate scientists looked at the atmospheric CO2 levels, then at the changes in climate which were occurring, and came up with the recommendation that a CO2 level of 350 ppm (last recorded back in 1987) was pretty much the upper allowable limit if massive climatic related adverse effects were to be avoided. The number 350 has a certain appealing ring to it, and has been widely adapted by environmental organizations such as Bill McKibben’s 350.org as a universal target for citizen and government action on carbon emissions. The protagonists are quite aware that the present global atmospheric CO2 level has already overshot that target by more than 40 ppm, but they argue, convincingly, that a reversal is absolutely essential to safeguard our long-term global future.

Fifth point – and now we’re at the crux of the problem. How on Earth, or anywhere else for that matter, do we get anywhere close to reducing the rate at which atmospheric CO2 increases in future, never mind actually reversing the trend towards 350 ppm?

We think of Earth’s carbon reservoirs as being great fields of coal and petroleum compounds, which are more or less stable until we dig them up and burn them. But the globe’s biggest carbon reservoirs are in the atmosphere, the ocean, living ecosystems and soils, and are highly dynamic. They all exchange CO2 with the atmosphere, they both absorb it (oceans) and assimilate it (ecosystems), and they release it (oceans) or respire it (ecosystems). The critical point is that anthropogenic carbon emitted into the atmosphere is not destroyed but adds to the stockpile and is redistributed among the other carbon reservoirs. The turnover times range from years or decades (living plants) to millennia (the deep sea, soil). The bottom line is that any carbon released into the atmosphere is going to be around for a long, long time. Up to 1000 years in fact.

Sixth point – so how do we get from our present scene of 390 ppm CO2 in the atmosphere and impending climate doom to something closer to 350 ppm and a more stable climate scenario? Straight answer – we cannot. We simply don’t have that option.

Seventh point – the absolutely best case scenario for reduction of CO2 emissions to the atmosphere would be an immediate halt to all activities leading to anthropogenic carbon emissions. Park all motor vehicles, no more home heating, no coal-fired power plants, no burning of natural gas, no aircraft flying overhead, shoot and bury 90% of all domestic livestock. Just shut down all of human civilization. No more anthropogenic carbon emissions. Would this sacrifice bring the CO2 level down in a hurry?

Dr Susan Solomon and her colleagues at NOAA, with the help of their sophisticate computer models have addressed that very question. They ran a coupled climate–carbon cycle model which has components representing the dynamic ocean, the atmospheric energy–moisture interaction, and interactive sub-models of marine and terrestrial carbon cycles. The model reveals, sadly for us, that climate change is largely irreversible for 1000 years after all carbon emissions cease. The drop in radiative forcing of atmospheric CO2 (i.e. the extent to which CO2 causes atmospheric warming) is largely compensated by slower loss of heat to the oceans. So atmospheric temperatures do not drop significantly for at least 1,000 years. And the natural interactive processes between the atmosphere, ocean and ecosystems would carry on. Atmospheric CO2 concentration would eventually drop back to 350 ppm by about 2060 and then flatten out to near 300 ppm for the rest of the 1000 years.

Eighth point – I haven’t noticed any great urges on the part of ourselves to go and huddle in caves and gnaw on pine nuts and raw fish (no wood-burning allowed) to make this scenario work, so what is more likely?

Global carbon emissions from fossil fuel use were 6.2 billion tonnes back in 1990 when global CO2 was near 355 ppm. The 2010 estimate is 8.5 billion tonnes. That’s a 38 % increase over the levels used to formulate the Kyoto Agreement. The annual growth rate of emissions derived from fossil fuels is now about 3.5%, an almost four-fold increase from the 0.9% per year for the 1990-1999 period. Carbon emissions from land-use change (i.e. mainly deforestation) in 2007 (in just that one year) were estimated at 1.5 billion tonnes of carbon. The biggest increase in emissions has taken place in developing countries, largely in China and India, while developed countries have been growing slower. The largest regional shift has been that China passed the U.S. in 2006 to become the largest CO₂ emitter, and India will soon overtake Russia to become the third largest emitter. Currently, more than half of the global emissions come from less developed countries. Developing countries with 80% of the world’s population still account for only 20% of the cumulative emissions since 1751. There is nowhere for these rates to go, other than up.

When the Intergovernmental Panel on Climate Change produced their Fourth Assessment Report in 2007, they diplomatically tried to hedge their bets. So they churned out 40 different scenarios based on emissions scenarios for the decade 2000-2010 which encompassed the full range of uncertainties related to future carbon emissions, demographic, social and economic inputs and possible future technological developments. The model predictions were correspondingly wide, ranging from “best” to “worst” in terms of atmospheric CO2 levels and changes in the associated climatic driving forces. Now it has become apparent that the actual emissions growth rate for 2000-2007 has exceeded the highest forecasted growth rates for 2000-2010 in their emissions scenarios.

Ninth point – so the most likely future outcomes (by the end of the century) are those at the top end of the scale outputted by the computer models (diagram above). That is to say our grandchildren will be looking at CO2 levels above 900 ppm, mean global temperature rises of 5 or 6 degrees C over what they are today, and an average sea level rise above 0.5 metres. Plus all the storms, cyclones, droughts, floods, vanishing shorelines, water wars and famines that might creep in along the way.

The end – CO2 concentrations in the atmosphere and future temperatures are just numbers, and pretty much the only things that computer models can output. We will have to estimate the extent of global human misery by ourselves.

An elder’s guide to climate scepticism

The other elders may drive me from the village with brooms and pitchforks when they read my confession. But the truth must out. I am, alas, a sceptic.

I am sceptical, as well as skeptical, that my beloved Earth is going to self-destruct on 31 December 2012. I think it’s more likely the Mayans ran out of wild fig bark on which they were drawing their calendars. I am sceptical that I am by nature diplomatic, charming and easygoing because Jupiter was hanging out with Venus in the Fourth House of the night sky right about the time I came into the world seventy-odd years ago. I am sceptical that the people responsible for the multi-billion dollar homeopathic remedy business have never learned to spell the words p-l-a-c-e-b-o and g-u-l-l-i-b-i-l-i-t-y. And all this scepticism flies in the teeth of the billions of people worldwide who buy into this stuff.

We sceptics are in good company. Albert Einstein was one.  In 1933 he famously stated that black holes do not and cannot exist. He couldn’t see one and couldn’t find the rationale for them in his famous equations. Today his successors have no such problems and not only think they have identified nearly 30 black hole candidates in the Milky Way galaxy but are now getting the proof that the holes behave in the relativistic way that Einstein’s theories predict.

But I’m concerned that we genuine sceptics are being given a bad name by all these so-called climate change and global warming sceptics out there.

We need to address a few issues to sort out these guys in the black hats. Firstly, what exactly is a sceptic? What is climate? And what is climate change and what does it entail?

The Oxford English Dictionary defines a sceptic as one who maintains a doubting attitude with reference to some particular question or statement. Michael Schermer, the entertaining editor of Skeptic magazine enlarges the concept thus:  “Modern skepticism is embodied in the scientific method that involves gathering data to formulate and test naturalistic explanations for natural phenomena. All facts in science are provisional and subject to challenge, and therefore skepticism is a method leading to provisional conclusions. The key to skepticism is to continuously and vigorously apply the methods of science to navigate the treacherous straits between “know nothing” skepticism and “anything goes” credulity”.

And what is ‘climate’ and how does it differ from ‘weather’?

Weather is the state of the atmosphere at any given moment to the extent that it is hot or cold, wet or dry, calm or stormy, clear or cloudy. The way the concept is used in daily life refers to day-to-day temperature and precipitation activity. By contrast climate is the term for the average atmospheric conditions over longer periods of time. The difference between the two creates major confusion for many.  “How the heck can it be global warming when we’re having record snowfalls in eastern Canada?”

Which leads us to the obvious next question – what is the evidence for climate change?

Lots of prestigious institutions keep honest meteorological data and report their findings. At the national level, Environment Canada reports that the national average temperature for 2010 was 3.0°C above normal, which makes it the warmest year on record since nationwide records began in 1948. The previous warmest year was 1998, 2.5°C above normal. Four Canadian climate regions (Arctic Tundra, Arctic Mountains and Fiords, North-eastern Forest and Atlantic Canada) experienced their warmest year on record in 2010, and for six other climate regions the year was amongst 10 warmest recorded.  Southern Alberta and Saskatchewan were the only parts of the country with close to normal temperatures. Environment Canada’s national temperature departures table shows that of the ten warmest years, four have occurred within the last decade, and 13 of the last 20 years are listed among the 20 warmest.

At the international level, the Climatic Research Unit of the University of East Anglia has global land and marine surface temperature data dating back to 1850. The Unit reports that the years 2003, 2005 and 2010 have been the warmest on record. The mean global temperature has risen by 0.8°C over the past century. The World Meteorological Organization reports that the ten warmest years on record have all occurred since 1998.

The U.S. Environmental Protection Agency has carefully summarized all the salient indicators of climate change occurring within the past century. These include:

• heat waves – the frequency of heat waves in the U.S. has risen steadily since 1970, and the area within the U.S. experi­encing heat waves has increased;
• average precipitation has increased since 1901 at an average rate of more than 6 percent per century in the U.S. and nearly 2 percent per century worldwide;
• heavy precipitation – in recent years, a higher percentage of precipitation in the U.S. has come in the form of intense single-day events; eight of the top 10 years for extreme one-day precipitation events have occurred since 1990;
• tropical cyclone intensity in the Atlantic Ocean, Caribbean, and Gulf of Mexico has risen noticeably over the past 20 years; six of the 10 most active hurricane seasons have occurred since the mid-1990s; this increase is closely related to variations in sea surface temperature in the tropical Atlantic;
• Arctic sea ice – September 2007 had the lowest ice coverage of any year on record, followed by 2008 and 2009; the extent of Arctic sea ice in 2009 was 24 percent below the 1979 to 2000 historical average;
• glaciers around the world have generally shrunk since the 1960s, and the rate at which glaciers are melting has accelerated over the last decade; overall, glaciers worldwide have lost more than 8000 km³ of water since 1960;
• lakes in the northern U.S. are freezing later and thawing earlier than they did in the 1800s and early 1900s; the length of time that lakes stay frozen has decreased at an average rate of one to two days per decade;
• snow cover over North America has generally decreased since 1972 (although there has been much year-to-year variability); snow covered an average of 8 million km² of North America during the years 2000 to 2008, compared with 8.8 million km² during the 1970s.

So we honest sceptics have no issue with the evidence for global warming. Its incontrovertible. Not even Sarah Palin could refudiate it.

What about the evidence for anthropogenic inputs to global climate change? In other words, to what extent are human activities, specifically the emission of carbon dioxide, methane and other greenhouse gases, responsible for the global warming observed to date?

Total global green house gas emissions (expressed as carbon dioxide equivalents) are nearing 30 billion metric tonnes per year. As a result mean global atmospheric carbon dioxide concentration has gone from about 280 parts per million during pre-industrial times to more than 380 parts per million today. Earlier CO₂ data were collected from ice-cores in eastern Antarctica and have been the subject of dispute by so-called climate sceptics, but the modern-day data come from state of the art instrumentation on Mauna Loa in Hawaii and are incontestable. From 1990 to 2008 the radiative forcing of all the greenhouse gases in the Earth’s atmosphere increased by about 26 percent, the rise in carbon dioxide concentrations accounting for approximately 80 percent of this increase.

It turns out that atmospheric CO₂ is not homogeneous. Some of it contains carbon-12, the rest carbon-13 (one more neutron per atom than carbon-12). Green plants prefer carbon-12 in their photosynthetic reactions. When fossil fuels, which are derived from ancient plants, are burned, the carbon-12 is release into the atmosphere. Over time the continuous carbon-12 emissions change the atmospheric proportion of carbon-13 to carbon-12, and this proportion can be measured in corals and sea sponges. So not only have background levels of CO₂ increased over the past century, they are directly linked to fossil fuel burning. And we honest sceptics are still cool with the concept.

Next question – is the extra anthropogenically-derived CO₂ responsible for the observed warming trend? The so-called ‘greenhouse’ effect of CO₂ is well-known, and can easily be measured in a laboratory. But it has also been measured globally over the past 30 years by satellite-mounted infrared sensors and found to be significant. Moreover, the amounts of global atmospheric downward long wave radiation over land surfaces measured from 1973 to 2008 have been examined and found to be significant in contributing to the global greenhouse effect.

The U.S. Protection Agency’s summary includes some biological indicators of long-term climate change in the U.S.:

• the average length of the growing season in the lower 48 states has increased by about two weeks since the beginning of the 20th century; a particularly large and steady increase having occurred over the last 30 years;  the observed changes reflect earlier spring warming as well as later arrival of fall frosts, and the length of the growing season has increased more rapidly in the west than in the east.
• plant hardiness zones have shifted northward since 1990, reflecting higher winter temperatures in most parts of the country; large portions of several states have warmed by at least one hardiness zone;
• leaf and bloom dates of lilacs and honeysuck­les in the lower 48 states are now a few days earlier than in 1900s;
• bird wintering ranges have shifted northward by an average of 56 km since 1966, with a few species shifting by several hundred kilometres; many bird species have moved their wintering grounds farther from the coast, consistent with rising inland temperatures.

So there you have it. Take all the scientific evidence available and it would be difficult indeed not to concur with the 97 out of 100 climate experts who think that humans are indeed causing global warming.

So, if the evidence satisfies the honest sceptics amongst us, i.e. those who take the time to seek out and evaluate the evidence and try their level best to come to an honest and defensible conclusions, why then is there a substantial body of opinion which holds countervailing views, i.e. that there is no warming or climate change (its all just natural variation), or that there is change but we ain’t responsible (its Mother Nature’s fault)?

That would be the subject of future postings from the Elders. It opens up the opportunity for some innovative taxonomy of climate change personalities, but I’ll leave the naming to others!

Climate change indicators

The evidence of human influences on climate change has become increas­ingly clear and compelling over the last several decades There is now convincing evidence that human activities such as electricity pro­duction and transportation are adding to the concen­trations of greenhouse gases that are already naturally present in the atmosphere. These heat-trapping gases are now at record-high levels in the atmosphere com­pared with the recent and distant past.

The U.S. Environmental Protection Agency has recently published Climate Change Indicators in the United States to help the concerned public readers interpret a set of important indicators  for climate change. The report presents 24 indicators, each describing trends in some way related to the causes and effects of climate change. The indicators focus primarily on the United States, but in some cases global trends are presented in order to provide context or a basis for comparison.  The following is a brief summary of the report’s contents.

Greenhouse Gases

Global Greenhouse Gas Emissions. Worldwide, emissions of greenhouse gases from human activities increased by 26 percent from 1990 to 2005. Emissions of carbon dioxide, which account for nearly three-fourths of the total, increased by 31 percent over this period. The majority of the world’s emissions are associated with energy use.

Atmospheric Concentrations of Greenhouse Gases. Concentrations of carbon dioxide and other greenhouse gases in the atmosphere have risen substantially since the beginning of the industrial era. Almost all of this increase is attributable to human activities. Histori­cal measurements show that the current levels of many greenhouse gases are higher than any seen in thousands of years, even after accounting for natural fluctuations.

Climate Forcing. From 1990 to 2008, the radiative forcing of all the greenhouse gases in the Earth’s atmosphere increased by about 26 percent. The rise in carbon dioxide concentrations accounts for approximately 80 percent of this increase. Radiative forcing is a way to measure how substances such as greenhouse gases affect the amount of energy that is absorbed by the atmosphere – an increase in radiative forcing leads to warming while a decrease in forcing produces cool­ing.

Weather and Climate

U.S. and Global Temperature. Average temperatures have risen across the lower 48 states since 1901, with an increased rate of warming over the past 30 years. Parts of the North, the West, and Alaska have seen temperatures increase the most. Seven of the top 10 warmest years on record for the lower 48 states have occurred since 1990, and the last 10 five-year periods have been the warmest five-year periods on record. Average global temperatures show a similar trend, and 2000–2009 was the warmest decade on record worldwide.

Heat Waves. The frequency of heat waves in the United States decreased in the 1960s and 1970s, but has risen steadily since then. The percentage of the United States experi­encing heat waves has also increased. The most severe heat waves in U.S. history remain those that occurred during the “Dust Bowl” in the 1930s, although average temperatures have increased since then.

Drought. Over the period from 2001 through 2009, roughly 30 to 60 percent of the U.S. land area experienced drought conditions at any given time. However, the data for this indicator have not been collected for long enough to determine whether droughts are increasing or decreasing over time.

U.S. and Global Precipitation. Average precipitation has increased in the United States and worldwide. Since 1901, precipitation has increased at an average rate of more than 6 percent per century in the lower 48 states and nearly 2 percent per century worldwide. However, shifting weather patterns have caused certain areas, such as Hawaii and parts of the Southwest, to experience less precipitation than they used to.

Heavy Precipitation. In recent years, a higher percentage of precipitation in the United States has come in the form of intense single-day events. Eight of the top 10 years for extreme one-day precipitation events have occurred since 1990. The occurrence of ab­normally high annual precipitation totals has also increased.

Tropical Cyclone Intensity. The intensity of tropical storms in the Atlantic Ocean, Caribbean, and Gulf of Mexico did not exhibit a strong long-term trend for much of the 20th century, but has risen noticeably over the past 20 years. Six of the 10 most active hurricane seasons have occurred since the mid-1990s. This increase is closely related to variations in sea surface temperature in the tropical Atlantic.

Oceans

Ocean Heat. Several studies have shown that the amount of heat stored in the ocean has increased substantially since the 1950s. Ocean heat content not only determines sea surface temperature, but it also affects sea level and currents.

Sea Surface Temperature. The surface temperature of the world’s oceans increased over the 20th century. Even with some year-to-year variation, the overall increase is statisti­cally significant, and sea surface temperatures have been higher during the past three decades than at any other time since large-scale measurement began in the late 1800s.

Sea Level. When averaged over all the world’s oceans, sea level has increased at a rate of roughly six-tenths of an inch per decade since 1870. The rate of increase has accelerated in recent years to more than an inch per decade. Changes in sea level relative to the height of the land vary widely because the land itself moves. Along the U.S. coastline, sea level has risen the most relative to the land along the Mid-Atlantic coast and parts of the Gulf Coast. Sea level has decreased relative to the land in parts of Alaska and the Northwest.

Ocean Acidity. The ocean has become more acidic over the past 20 years, and studies suggest that the ocean is substantially more acidic now than it was a few centuries ago. Rising acidity is associated with increased levels of carbon dioxide dissolved in the water. Changes in acidity can affect sensitive organisms such as corals.

Snow & Ice

Arctic Sea Ice. Part of the Arctic Ocean stays frozen year-round. The area covered by ice is typically smallest in September, after the summer melting season. September 2007 had the least ice of any year on record, followed by 2008 and 2009. The extent of Arctic sea ice in 2009 was 24 percent below the 1979 to 2000 historical average.

Glaciers. Glaciers in the United States and around the world have generally shrunk since the 1960s, and the rate at which glaciers are melting appears to have accelerated over the last decade. Overall, glaciers worldwide have lost more than 2,000 cubic miles of water since 1960, which has contributed to the observed rise in sea level.

Lake Ice. Lakes in the northern United States generally appear to be freezing later and thawing earlier than they did in the 1800s and early 1900s. The length of time that lakes stay frozen has decreased at an average rate of one to two days per decade.

Snow Cover. The portion of North America covered by snow has generally decreased since 1972, although there has been much year-to-year variability. Snow covered an average of 3.18 million square miles of North America during the years 2000 to 2008, compared with 3.43 million square miles during the 1970s.

Snowpack. Between 1950 and 2000, the depth of snow on the ground in early spring decreased at most measurement sites in the western United States and Canada. Spring snowpack declined by more than 75 percent in some areas, but increased in a few others.

Society & Ecosystems

Heat-Related Deaths. Over the past three decades, more than 6,000 deaths across the United States were caused by heat-related illness such as heat stroke. However, consider­able year-to-year variability makes it difficult to determine long-term trends.

Length of Growing Season. The average length of the growing season in the lower 48 states has increased by about two weeks since the beginning of the 20th century. A particularly large and steady increase has occurred over the last 30 years. The observed changes reflect earlier spring warming as well as later arrival of fall frosts. The length of the growing season has increased more rapidly in the West than in the East.

Plant Hardiness Zones. Winter low temperatures are a major factor in determining which plants can survive in a particular area. Plant hardiness zones have shifted noticeably northward since 1990, reflecting higher winter temperatures in most parts of the country. Large portions of several states have warmed by at least one hardiness zone.

Leaf and Bloom Dates. The timing of natural events such as leaf growth and flower blooms are influenced by climate change. Observations of lilacs and honeysuck­les in the lower 48 states indicate that leaf growth is now occurring a few days earlier than it did in the early 1900s. Lilacs and honeysuckles are also blooming slightly earlier than in the past, but it is difficult to determine whether this change is statistically meaningful.

Bird Wintering Ranges. Some birds shift their range or alter their migration habits to adapt to changes in temperature or other environmental conditions. Long-term stud­ies have found that bird species in North America have shifted their wintering grounds northward by an average of 35 miles since 1966, with a few species shifting by several hundred miles. On average, bird species have also moved their wintering grounds farther from the coast, consistent with rising inland temperatures.