“Cause” vs. “contribute” are really two different, but related, questions.  By way of illustration we can start with a couple of very fundamental facts.  Warm water evaporates more quickly that cold water, and warm air holds more moisture than cooler air.  Thousands of global temperature measurements tell us that the oceans and the atmosphere are warming, therefore moisture is being added to the atmosphere more rapidly and the air has the capacity to hold more moisture.  Therefore it stands to reason global warming may contribute to the intensity of individual rainfall events and may even cause them.  

However, the ability to quantify any effect of climate change upon rainfall, and to scientifically prove a cause and effect relationship is a more difficult task.   Two recent papers in the on-line version of the esteemed British journal, Nature, have addressed this topic.  The first, “Human contribution to more intense precipitation extremes”⁽¹⁾ compared  50 years of precipitation records (1951 – 1999) over much of the northern hemisphere with the results of several computer models used to predict 20th century precipitation.  It was only when the effects of greenhouse gases was added to the models that agreement with the actual measured precipitation was obtained.  The study showed an increase of 7% in the probability of extreme precipitation on any given day during the later half of the 20th century in the Northern Hemisphere, a far greater percentage than would be expected from the natural variability of weather.  A second finding was that existing climate models tend to be conservative in predicting precipitation, typically underestimating the amount that was actually measured.

With a more narrow geographic scope, another paper “Anthropogenic greenhouse gas contribution to flood risk in England and Wales in autumn 2000” ⁽²⁾ examined the data from a single, regional event, the wettest autumn since records began in 1766, and found that the chances of such  heavy floods as the region experienced in the fall of 2000 were roughly doubled by the increased level of greenhouse gases in the atmosphere.  Nine out of ten of their computer model simulations showed that anthropogenic greenhouse gas emissions increased the probably of such flooding as experienced in 2000 by over 20%, while two-thirds of the simulations showed an increased probability of over 90%.

The fact that both of these groundbreaking studies took nearly 10 years to complete, even when an base of actual data existed, shows the tremendous amount of computer time that the highly complex climate models require.  While such models may not be perfect, they are rapidly becoming more accurate, and as demonstrated here, capable of more highly refined results; and they are definately the best available tools for understanding climate change.   Note that in both cases, these studies are not saying that specific weather events were directly caused by climate change, but rather that the probabilities of their occurrence was increased by climate change. It is also noteworthy that the second study, dealing with the 2000 flood risk in England and Wales, was conducted by the ClimatePrediction.net project at Oxford University, using a computer grid composed of approximately 60,000 donations of unused computer cycles on individual personal computers around the world.

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1.) Human contribution to more-intense precipitation extremes: http://www.nature.com/nature/journal/v470/n7334/full/nature09763.html

2.) Anthropogenic greenhouse gas contribution to flood risk in England and Wales in autumn 2000: http://www.nature.com/nature/journal/v470/n7334/full/nature09762.html

The January 29th announcement establishes the targets required by the October 5, 2009 Executive Order 13514 (Federal Leadership in Environmental, energy and Economic Performance) mandated that Federal Agencies submit a 2020 greenhouse gas reduction target within 90 days; and, increase energy efficiency, reduce petroleum consumption, conserve water, reduce waste and increase recycling.

The announcement does not include any emission reductions by federal contractors and suppliers, or resulting from employee commuting as called for by the executive order.

The full text of the White House announcement is:

The White House

Office of the Press Secretary

For Immediate Release

January 29, 2010

President Obama Sets Greenhouse Gas Emissions Reduction Target for Federal Operations

 

Target to Drive Energy Cost Reductions in Federal Operations, Creating Clean Energy Jobs

WASHINGTON, DC – President Barack Obama today announced that the Federal Government will reduce its greenhouse gas (GHG) pollution by 28 percent by 2020.  Reducing and reporting GHG pollution, as called for in Executive Order 13514 on Federal Sustainability, will ensure that the Federal Government leads by example in building the clean energy economy.  Actions taken under this Executive Order will spur clean energy investments that create new private-sector jobs, drive long-term savings, build local market capacity, and foster innovation and entrepreneurship in clean energy industries.

As the single largest energy consumer in the U.S. economy, the Federal Government spent more than $24.5 billion on electricity and fuel in 2008 alone.  Achieving the Federal GHG pollution reduction target will reduce Federal energy use by the equivalent of 646 trillion BTUs, equal to 205 million barrels of oil, and taking 17 million cars off the road for one year.  This is also equivalent to a cumulative total of $8 to $11 billion in avoided energy costs through 2020.

“As the largest energy consumer in the United States, we have a responsibility to American citizens to reduce our energy use and become more efficient,” said President Obama.  “Our goal is to lower costs, reduce pollution, and shift Federal energy expenses away from oil and towards local, clean energy.”

Federal Departments and Agencies will achieve greenhouse gas pollution reductions by measuring their current energy and fuel use, becoming more energy efficient and shifting to clean energy sources like solar, wind and geothermal.  Examples of agency actions that are underway are available on the White House Council on Environmental Quality website and can be found at www.whitehouse.gov/ceq.

On October 5, 2009, President Obama signed Executive Order 13514 on Federal Sustainability, setting measureable environmental performance goals for Federal Agencies.  Each Federal Agency was required to submit a 2020 GHG pollution reduction target from its estimated 2008 baseline to the White House Council on Environmental Quality and to the Director of the Office of Management and Budget by January 4, 2010.  The Federal target announced today is the aggregate of 35 Federal Agency self-reported targets.

Greenhouse gas emissions serve as a useful metric to measure the effectiveness of agency energy and fuel efficiency efforts as well as renewable energy investments. Agencies are already taking actions that will contribute towards achieving their targets, such as installing solar arrays at military installations, tapping landfills for renewable energy, putting energy management systems in Federal buildings, and replacing older vehicles with more fuel efficient hybrid models.

As a next step, the Office of Management and Budget will validate and score each agency’s sustainability plan, assuring a long-term return on investment to the American taxpayer. To ensure accountability, annual progress will be measured and reported online to the public.

There are three basic options that governments can implement to regulate pollutant discharges:  “cap and trade”, “cap” and “tax”.

Under a “cap and trade” scheme the government establishes a “cap” on the amount of pollutant, say CO2, that an industry can discharge into the environment.  The cap is lowered at regular intervals, thus reducing the total amount of pollutant that can be discharged.   Businesses must then buy “allowances” to discharge, either from the government or at specially created, open market “trading” exchanges (comparable to a stock exchange).

• The selling of allowances has the potential to generate vast sums of money for the government.  It is thus in the governments interest to sell more allowances during difficult fiscal times, with fiscal needs and politics becoming the driving factor.
• Proponents claim that the selling and trading of pollution allowances “moniterizes” the pollutant, or turns it into a commodity with a defined value.
• Cap and trade requires the establishment of a vast bureaucracy to establish and regulate the caps and to establish and regulate the trading exchanges.
• Cap and trade creates a vast new constituency  of lawyers, lobbyists, traders, investment banks, hedge funds and other speculators; all of whom have a vested interest in perpetuating the scheme.
• A cap and trade scheme is inherently complex few, in any, individuals being in a position to have a good understanding of the entire operation. Consequently cap and trade creates large opportunities for graft, fraud and abuse.
• Due to the complexity of the scheme, cap and trade is usually applied only to large companies, leaving vast numbers of individual and businesses free to pollute as much as they want.
• Under a cap and trade scheme, the cost of the required large bureaucracies will be passed on to the taxpayers.  Businesses and utilities will also pass on to the consumer the cost of their allowances, whether purchased from the government or at trading exchanges.  And, when the cap is lowered to the point that available allowances will no longer cover a businesses discharges, companies will be forced to install new equipment or otherwise reduce emissions; at a cost which will again be passed on to the consumer.  Note that it is only this last, of three, cost that provides any benefits to the consumer.
• Cap and trade schemes have not proven to be universally successful, especially as the profit motive both on the part of governments and trades often obscures the intended purpose.

Under a “cap” or “regulatory” scheme the government would merely place a “cap” on emissions and issue discharge permits to businesses and utilities.  In essence such a scheme would be no different than the current  processes used to regulate discharge of pollutants into waterways.  In the United States, the government has just placed a “cap” on 2016 tailpipe emissions of CO2 from vehicles of 250 grams per mile, a 34% reduction from the 2009 models.  There appears to be no justifiable reason that a government could not just as easily place a CO2 cap on all CO2 discharges, including those from industry.

• Under a pure regulatory cap, the government would not receive money from the sale of pollution allowances.
• There would be no trading exchanges, since there would be nothing to trade, and thus no establishment of a constituency dedicated to preserving the right to pollute. And the opportunities for graft, corruption and abuse would be greatly decreased.
• Essentially all developed nations have an environmental regulatory agency, so there is no need to establish a new, separate bureaucracies as required under a cap and trade scheme.  No doubt, the existing regulatory agencies might need to be expanded, but new agencies and their associated costs would not be needed.
• The governmental costs borne by taxpayers would be minimal compared to a cap and trade scheme, and there would be no costs of allowances for businesses to pass on to consumers. Consumers would share only the costs of new equipment and practices to reduce pollution, as passed on by businesses.  Thus consumers would pay only one cost, rather than three, to obtain the desired environmental benefits.
• Since a purely regulatory cap removes profit opportunities, opponents claim that it would be politically unpalatable.   But the fact remains that in the long run, a pure regulatory cap would be just as effective, and far cheaper for all involved, that a cap and trade scheme.

While there are several variations, a carbon tax is by far the simplest means of lowering CO2 emissions.  Most tax proposals are for a “rising”, “rebated” tax under which the tax would be steadily raised (just as a cap is lowered), and the collected tax dollars are rebated to consumers.  As the cost of energy increases, market forces would lower carbon fuel consumption, and thus reduce CO2 emissions.  In theory, consumers would choose energy-efficient products and adopt conservation practices, while energy efficient businesses would have a competitive advantage.  In practice, CO2 emissions in the United States actually decreased 2.8% in 2008 – a decrease attributed to high gasoline prices and a sagging economy.  Upon closer examination, we find that CO2 emissions of the transportation sector actually decreased by 5.2% and that CO2 emissions per dollar of economic output decreased by 3.8%; both decreases indicating that the high cost of energy was the major contributing factor rather than the economic downturn.

• Virtually all developed nations have a well established, and experienced bureaucracy dedicated to the collection and rebating of taxes.  While the tax agencies might need to be expanded to cover an increased workload the cost would be minimal.
• Any added cost would be minimal.
• Opportunities for fraud, corruption and abuse would be no greater than under current tax practices.
• If the tax is equally rebated to taxpayers, those who consume an average amount of energy would break even, while those who consume less energy than the average would actually make money, thus providing an economic incentive to conserve energy.  Also, while all surveys show that energy usage tends to increase with income, those with a low income would tend to receive a larger rebate than their energy taxes paid.  (More lower income people utilize public transportation than drive Hummers.)
• The base cost of energy and any increased cost of manufactured products would be driven by competitive market forces.
• As the energy tax rises, and oil consumption decreases, more dollars would remain at home, rather than being shipped to the oil producing nations.
• Any additional tax would be difficult to implement since citizens of all nations abhor taxes.  Therefore implementation of a rising, rebated tax scheme will require political foresight and courage.  However, a rising, rebated tax scheme is by far the cheapest alternative, and of proven effectiveness.

The need to address climate change is urgent.  We do not have the time to experiment with various schemes to lower CO2 emissions, but rather must get it right the first time.  Citizens should inform themselves on the issues and possible actions, and demand that our political leaders have the courage to do what is right, not what is “expedient”.

Release date: 04/17/2009

(Washington, D.C. – April 17, 2009) After a thorough scientific review ordered in 2007 by the U.S. Supreme Court, the Environmental Protection Agency issued a proposed finding Friday that greenhouse gases contribute to air pollution that may endanger public health or welfare.

The proposed finding, which now moves to a public comment period, identified six greenhouse gases that pose a potential threat.

“This finding confirms that greenhouse gas pollution is a serious problem now and for future generations. Fortunately, it follows President Obama’s call for a low carbon economy and strong leadership in Congress on clean energy and climate legislation,” said Administrator Lisa P. Jackson. “This pollution problem has a solution – one that will create millions of green jobs and end our country’s dependence on foreign oil.”

As the proposed endangerment finding states, “In both magnitude and probability, climate change is an enormous problem. The greenhouse gases that are responsible for it endanger public health and welfare within the meaning of the Clean Air Act.”

EPA’s proposed endangerment finding is based on rigorous, peer-reviewed scientific analysis of six gases – carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride – that have been the subject of intensive analysis by scientists around the world. The science clearly shows that concentrations of these gases are at unprecedented levels as a result of human emissions, and these high levels are very likely the cause of the increase in average temperatures and other changes in our climate.

The scientific analysis also confirms that climate change impacts human health in several ways. Findings from a recent EPA study titled “Assessment of the Impacts of Global Change on Regional U.S. Air Quality: A Synthesis of Climate Change Impacts on Ground-Level Ozone,” for example, suggest that climate change may lead to higher concentrations of ground-level ozone, a harmful pollutant. Additional impacts of climate change include, but are not limited to:

• increased drought;
• more heavy downpours and flooding;
• more frequent and intense heat waves and wildfires;
• greater sea level rise;
• more intense storms; and
• harm to water resources, agriculture, wildlife and ecosystems.

In proposing the finding, Administrator Jackson also took into account the disproportionate impact climate change has on the health of certain segments of the population, such as the poor, the very young, the elderly, those already in poor health, the disabled, those living alone and/or indigenous populations dependent on one or a few resources.

In addition to threatening human health, the analysis finds that climate change also has serious national security implications. Consistent with this proposed finding, in 2007, 11 retired U.S. generals and admirals signed a report from the Center for a New American Security stating that climate change “presents significant national security challenges for the United States.” Escalating violence in destabilized regions can be incited and fomented by an increasing scarcity of resources – including water. This lack of resources, driven by climate change patterns, then drives massive migration to more stabilized regions of the world.

The proposed endangerment finding now enters the public comment period, which is the next step in the deliberative process EPA must undertake before issuing final findings. Today’s proposed finding does not include any proposed regulations. Before taking any steps to reduce greenhouse gases under the Clean Air Act, EPA would conduct an appropriate process and consider stakeholder input. Notwithstanding this required regulatory process, both President Obama and Administrator Jackson have repeatedly indicated their preference for comprehensive legislation to address this issue and create the framework for a clean energy economy.

Contact Information: Cathy Milbourn, 202-564-4355 / 7849 / milbourn.cathy@epa.gov; En español: Lina Younes, 202-564-4355 / younes.lina@epa.gov

More information: http://epa.gov/climatechange/endangerment.html