UCS: Report Confirms Human Activity Driving Global Warming

February 2, 2007
From Union of Concerned Scientists.

Authoritative Report Confirms Human Activity Driving Global Warming

Strongest evidence yet that human activity is causing warming in atmosphere, land, and oceans.

WASHINGTON—After six years of assessing climate science research from around the world, the United Nation's Intergovernmental Panel on Climate Change (IPCC) has solidified the scientific understanding that key heat-trapping gases in the atmosphere "have increased markedly as a result of human activities," and the "net effect of human activities since 1750 has been one of warming." The report states that evidence of the climate's warming "is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level."

"This report reaffirms that our emissions are the primary cause of global warming," said Peter Frumhoff, Director of Science and Policy at UCS. "The good news is that by taking action today to dramatically reduce our emissions, we can avoid much of the warming projected in this report."

The new IPCC Working Group I Summary for Policymakers synthesizes the current understanding of climate change and projects future climate change using the most comprehensive set of well-established global climate models. The report is the first of three major studies that comprise the IPCC Fourth Assessment, with input from more than 1,200 authors and 2,500 scientific expert reviewers from more than 130 countries. Subsequent reports will evaluate global warming consequences and options for reducing future warming.

The report confirms that the current level of carbon dioxide, a critical heat-trapping gas in the atmosphere, "exceeds by far the natural range over the last 650,000 years." Since the dawn of the industrial era, carbon dioxide and other key heat-trapping gases have increased at a rate that is "very likely to have been unprecedented in more than 10,000 years."

This unprecedented increase has led to warming of the atmosphere, land, and ocean:

• Eleven of the last twelve years rank among the twelve hottest years on record.
  
• "The maximum area covered by seasonally frozen ground has decreased by about 7 percent in the Northern Hemisphere since 1900, with a decrease in spring of up to 15 percent."
  
• "More intense and longer droughts have been observed over wider areas since the 1970s, particularly in the tropics and subtropics." Droughts have been linked to changes in sea surface temperatures and wind patterns and decreased snowpack and snow cover.
  

"This evidence is a wake up call and we need to stop hitting the snooze button," said UCS climate scientist Brenda Ekwurzel. "Will we take sufficient action to avoid the worst effects of global warming or resign ourselves to the consequences of a very different climate?"

Even if we act today to reduce our emissions from cars, power plants, and other sources, past emissions will commit us to more warming since they stay in the atmosphere for decades. The report concludes that if we take no action to reduce emissions, there will be twice as much warming over the next two decades than if we had stabilized heat-trapping gases at 2000 levels. Among other changes, the models also:

• Find it is likely that future tropical cyclones (typhoons and hurricanes) will become more intense, with higher peak wind speeds and more heavy precipitation associated with warmer tropical seas.
  
• Suggest that if global average temperatures were to exceed 1.9 to 4.6 degrees C (3.4 to 8.3 degrees F) compared to pre-industrial temperatures, the Greenland ice sheet would lose mass faster than it gains, producing a net contribution to sea level rise. If sustained, the loss of ice would eventually lead to complete elimination of the Greenland ice sheet and contribute an additional 23 feet to sea level rise.
  
• Project a greater than 90 percent likelihood that hot extremes, heat waves, and heavy precipitation events will continue to become more frequent.
  

"What we've observed and what we expect to see make it critical that we meaningfully reduce our emissions," said Ekwurzel. "We can still avoid catastrophic climate change, but only if we start today."



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Livestock generate 18 percent of world's greenhouse gases

A new report by the United Nations Food and Agriculture Organization found that domestic animals are a major source of greenhouse gases, producing 18% of the world's total - even more than transportation. Unless more sustainable techniques such as controlling soil erosion, providing animals with better diets, and using water more efficiently are adopted, the environmental impact of animal production will worsen, as world production of meat and dairy products is expected to double by 2050.

Source: Union of Concerned Scientists.
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The Reality of Nuclear Power

Good evening. My name is David Lochbaum. I have been the Nuclear Safety Engineer for Union of Concerned Scientists for the past three years. Prior to joining UCS, I worked for over 17 years as a nuclear engineer in the nuclear industry. Between 1992 and 1995, I was a consultant to the New York Power Authority working primarily on their FitzPatrick nuclear power plant and some on their Indian Point Unit 3 facility.

I am going to speak a little bit about the history of nuclear power, but will focus more on its future. Many people have stated recently that the nuclear industry is at a crossroads because of electric utility deregulation. I personally do not subscribe to that theory because it implicitly implies either that we are all going in a big circle because we reach a crossroad every three or four months or that we are not moving at all and remain at the first crossroad we reached.

Workers at the Shippingport nuclear power plant outside Pittsburgh, Pennsylvania, flipped a switch in December 1957 to connect the plant's turbine-generator to the electrical grid. This marked the first time that a civilian utility company in the United States supplied electricity to its customers from nuclear power. In the subsequent four decades, nuclear power has generated billions of kilowatts of electricity, several thousand tons of highly radioactive waste, and immeasurable controversy.

Proponents claim that nuclear power is vital if the United States is to have energy independence and to combat global warming. Antinuclear activists claim that nuclear power plants are unacceptably risky and that nuclear waste is the wrong legacy for us to leave future generations.

This debate is what I call the politics of nuclear power. Three years of working inside the DC beltway have taught me one important lesson -- I don't want to work in politics, particularly the politics of nuclear power.

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