Is climate change really happening?

Yes. In February 2007, the Intergovernmental Panel on Climate Change (IPCC) reported to the United Nations that the Earth’s climate system is undoubtedly getting warmer.

According to the Climate Impacts Group at the University of Washington, the average annual temperature in the Pacific Northwest rose by 1.5° F in the 20th century and is expected to rise 0.5° F per decade in the first half of the 21st century.

The graph below shows the global annual temperature change since 1880. Even with variation over the years, the general trend is clearly upward. Some cooler temperatures in recent years have prompted people to ask if there is now a global cooling trend, but as the graph shows, even several years of cooling doesn’t mean a long-term warming trend is over.

The land-ocean temperature index combines data on air temperatures over land with data on sea surface temperatures. (“Mean” is the midpoint between the highest and lowest.) The black line shows the annual changes; the red line tracks 5-year periods. Source: NASA Goddard institute for Space Studies. (January 11, 2008)

Although specific, individual events can’t be directly linked to global warming, the IPCC has noted many indications of climate change around the world:

· Retreating mountain glaciers on all continents

· Thinning ice caps in the Arctic and Antarctic

· Rising sea level – about 6-7 inches in the 20th century

· More frequent heavy precipitation events (rainstorms, floods or snowstorms) in many areas

· More intense and longer droughts over wider areas, especially in the tropics and subtropics

References:

Intergovernmental Panel on Climate Change – Climate Change 2007: The Physical Science Basis, Summary for Policy Makers; 2007

Date: 2015-04-20; view: 978