While fewer and fewer people are willing to publicly deny the validity of global warming science, those who oppose action to protect the climate have taken up a new strategy: Denying that climate change will have a major impact on the US economy.

This denial is rejected by most economists who have studied climate change. In a survey of 144 top climate economists released November 4, 2009, by the Institute for Policy Integrity at the New York University School of Law, 84 percent agreed that "the environmental effects of greenhouse gas emissions, as described by leading scientific experts, create significant risks to important sectors of the United States and global economies." A majority stated that sectors that will be negatively affected include agriculture, fishing, forestry, insurance and health services.

But the profound negative economic impact of climate change is being largely ignored or denied in the current public policy debate. This denial threatens to have a significant effect on public policy. For example, testimony October 14, 2009, by Douglas W. Elmendorf, the director of the Congressional Budget Office, states, "Most of the economy involves activities that are not likely to be directly affected by changes in climate." He claims that "a relatively pessimistic estimate for the loss in projected real gross domestic product is about 3 percent for warming of about 7 degrees Fahrenheit (F) by 2100." He cites only two studies, one published in 2004; the other, which he describes as "the most comprehensive published study," was published in 2000, a decade before current research on the impacts of climate change.

This testimony completely ignores the British government's 700-page "Stern Review," widely regarded as the most definitive study so far of the economic impact of global warming, released on October 30, 2006, by former World Bank chief economist Nicholas Stern. It states, "Our actions over the coming few decades could create risks of major disruption to economic and social activity, later in this century and in the next, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20th century."

The CBO testimony ignores many studies that indicate significant negative effects of climate change on the US economy in the coming years. For example, a study by the University of Maryland found that "the costs of climate change rapidly exceed benefits and place major strains on public sector budgets, personal income and job security. Because of the economic costs of climate change, we conclude that delayed action (or inaction) on global climate change will likely be the most expensive policy option."

The CBO testimony ignores the June 16, 2009, government report "Global Climate Change Impacts in the US," issued by the US Global Change Research Program, which described economically devastating results of global warming already under way:

• More rain is already coming in very heavy events, and this is projected to increase across the nation. This would have impacts on transportation, agriculture, water quality, health, and more;

   

• Heat waves will become more frequent and intense, increasing threats to human health and quality of life, especially in cities;

   

• Warming will decrease demand for heating energy in winter and increase demand for cooling energy in summer. The latter will increase peak electricity demand in most regions;

   

• Water resources will be stressed in many regions. For example, snowpack is declining in the West, and there is an increasing probability of drought in the Southwest, while floods and water quality issues are likely to be more of a problem in most regions;

   

• In coastal communities, sea-level rise and storm surge will increase threats to homes and infrastructure including water, sewer, transportation and communication systems.

One small example of the way impacts of climate change are ignored: The CBO testimony states that the "medical care" sector will be "relatively insulated from climate effects." "Global Climate Change Impacts in the US" states on the contrary, "Climate change poses unique challenges to human health including heat waves and severe storms, ailments caused or exacerbated by air pollution and airborne allergens, and many climate-sensitive infectious diseases."

The CBO testimony also ignores a new study by the Union of Concerned Scientists, "Climate Change in the United States: The Prohibitive Costs of Inaction." After reviewing effects on flooding, hurricane intensity, tourism, public health, water scarcity, shipping, agriculture, energy and infrastructure stress and wildfires, the study concludes, "If global warming emissions continue unabated, every region in the country will confront large costs from climate change in the form of damages to infrastructure, diminished public health, and threats to vital industries employing millions of Americans ... These projected costs of climate change do not include those that are critical but hard to quantify, such as costs stemming from changes to ecosystems and the need to relocate coastal communities."

The CBO testimony acknowledges that "there is a small possibility that even relatively modest warming could trigger abrupt and unforeseen effects during the 21st century that could result in large economic costs in the United States." It concludes, "The sources and nature of such abrupt changes, their likelihood, and their potential impacts remain very poorly understood." Thereafter, it largely disregards such effects as melting ice caps and glaciers, rising sea levels, epidemic diseases and extreme weather events, even though a great deal of scientific evidence has emerged on these threats in recent years.

Such denial leads to a deadly miscalculation of the economic cost of failure to counter global warming. The CBO acknowledges that "unchecked increases in greenhouse-gas emissions" would "probably reduce output over time, especially later in this century." However, the CBO concludes that the net effects on GDP of restricting emissions in the United States are likely to be negative over the next few decades. That conclusion results from a total failure to consider the devastating impact of climate change on the global and US economies, as revealed, for instance, in the "Stern Review."

How many epidemics and Katrinas will it take to expose the myth that the US economy is somehow exempt from the threats of climate change? And what terrible price will we pay if we shun the cost of climate protection, but not the far greater cost of climate change?