Global Warming Signs in Summer

Scientists See Summer Full of Global Warming Signs

This summer's wildfires in Russia, floods in Pakistan, torrential rainfall in China and sweltering heat waves in 15 (out of 50) U.S. states are all signs of the effects of global warming identified by scientists in the U.S. Global Change Research Program, according to the Union of Concerned Scientists (UCS).

In its report, Global Climate Change in the United States, the U.S. Global Change Research Program predicted that climate change associated with global warming would trigger devastating heat, along with unusually heavy rains in some parts of the world, and extended droughts in others.

While heavy rains may not seem consistent with a warming world, they are, says the Union of Concerned Scientists. "While it may seem counterintuitive, a warming planet generates more precipitation in regions that typically experience rain or snow. That is because a warmer atmosphere absorbs and retains more water from the soil and water bodies--lakes, rivers and oceans. Where storm clouds gather, the atmosphere typically has more water to dump, producing heavier-than-normal storms."

The villain, according to the Concerned Scientists and the U.S. Global Change Research Program, is the ongoing burning of fossil fuels which causes a build-up of heat-trapping greenhouse gases in the atmosphere, resulting in a steady increase in the Earth's average temperature.

"Climate scientists have been warning for years about the potential for intense heat waves, droughts and drenching rains in various parts of the world," said Brenda Ekwurzel, a climate scientist with the UCS in a press release. "This intense weather is consistent with well-documented climate change trends over the past several decades. Unless we significantly reduce global warming emissions, we'll likely see even more extreme weather events."

What is Global Warming-Video

This video explains the concept of global warming, which is generally thought to be caused by human driven emissions of greenhouse gasses, such as carbon dioxide.

What is Global Warming?

Global warming is the increase in the average temperature of Earth's near-surface air and oceans since the mid-20th century and its projected continuation. According to the 2007 Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC), global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 20th century. Most of the observed temperature increase since the middle of the 20th century was caused by increasing concentrations of greenhouse gases, which results from human activity such as the burning of fossil fuel and deforestation. Global dimming, a result of increasing concentrations of atmospheric aerosols that block sunlight from reaching the surface, has partially countered the effects of greenhouse gas induced warming.

Climate model projections summarized in the latest IPCC report indicate that the global surface temperature is likely to rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the 21st century. The uncertainty in this estimate arises from the use of models with differing sensitivity to greenhouse gas concentrations and the use of differing estimates of future greenhouse gas emissions. An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, probably including expansion of subtropical deserts.Warming is expected to be strongest in the Arctic and would be associated with continuing retreat of glaciers, permafrost and sea ice. Other likely effects include changes in the frequency and intensity of extreme weather events, species extinctions, and changes in agricultural yields. Warming and related changes will vary from region to region around the globe, though the nature of these regional variations is uncertain.

The scientific consensus is that anthropogenic global warming is occurring.Nevertheless, political and public debate continues. The Kyoto Protocol is aimed at stabilizing greenhouse gas concentration to prevent a "dangerous anthropogenic interference". As of November 2009, 187 states have signed and ratified the protocol.