A report released Tuesday by the U.N. Foundation and Sigma Xi, a scientific research society, said exceeding 2 to 2.5 degrees Celsius above the pre-industrial global temperature levels in the year 1750 would "sharply increase the risk of intolerable impacts" on the present-day environment. Researches expect continuing increases of 0.2 to 0.4 degrees Celsius per decade with potential abrupt peaks and valleys in weather patterns.
Significant harm could result.
Even small increases in global temperatures could have impacts including a rise in sea level, more frequent heat waves, droughts, extreme weather occurrences like torrential rains and floods, increased tropical diseases in now-temperate regions, and intensified hurricanes. It could lead to a significant reduction in agricultural output, especially in poor countries.
"Humanity must act collectively and urgently to change course through leadership at all levels of society," said the report, "Confronting Climate Change: Avoiding the Unmanageable and Managing the Unavoidable," released at U.N. World Headquarters in New York. "There is no more time for delay."
Avoiding going over the 2-2.5 degrees Celsius limit requires the stabilization of atmospheric concentrations, according to the study. This requires global carbon dioxide emissions to peak no later than 2015-2020 at not much above their current level and decline by 2100 to approximately a third of the 2100 readings.
The technology is available to reduce the emissions, said the report, but policy makers must act immediately by improving efficiency in the transportation sector, improving design of commercial and residential buildings, and expanding the use of bio-fuels by use of incentives, the report said.
If no action is taken, an increase of refugees from flooding or famine, violent conflicts and international instability could result, which could lead to more security threats worldwide.
In addition, the study said, poor nations and poor individuals who are affected by this climate change have fewer resources available to manage major challenges and threats. The consequences of global warming will hit the poor the hardest partly because those areas likely to be significantly affected first are in the poorest regions of the world.
The scientists suggested a new framework to address the problems.
The report calls for a new global policy framework through an international agreement to a target of no more than the 2-2.5 degrees Celsius temperature increase. Their proposal also urges establishing a price on carbon emissions in all countries and to create mechanisms to pay for low-emitting technologies for low-come countries.
As to whether the United States would climb aboard these initiatives, the chances look slim under the Bush administration who has repeatedly rebuffed global solutions, such as the Kyoto Protocol. The administration has also rejected the idea of an international agreement after Kyoto expires in 2012.
On a more promising note, the Democratic leadership in Congress has made global warming a priority, holding hearings on the topic. In the past few weeks the climate problem has been highlighted in Congress with the release of a report by the Intergovernmental Panel on Climate Change, which brings together 2,500 scientists from more than 130 countries. They predicted average world temperature will rise by approximately 3 degrees by the end of the century. They also confirmed, with 90 percent certainty, humans are to blame for the increase in temperature.
"This report defines the seriousness and urgency that must characterize global efforts to respond to the unfolding and far-reaching challenge of climate change," said Timothy Wirth of the U.N. Foundation report.
Said John Holdren, a Harvard University professor of environmental policy, "It is still possible to avoid an unmanageable degree of climate change, but the time for action is now."