Persistent droughts in China, East Africa, the western United States, and northern Mexico; devastating floods in Pakistan and Kentucky, severe heat waves in Europe and the northwestern United States, destructive cyclones in Southeast Africa, and intense hurricanes in the United States and Central America are just a few of the weather events that scientists have been predicting for years. years as a result of global warming.
“Since pre-industrial times the temperature has risen by just one degree and we are already seeing more extreme weather patterns,” said Elizabeth Robinson, director of London’s Grantham Research Institute.
EDITOR’S NOTE: This dispatch is part of a series on the most serious problems associated with climate change, the role of science, the impact of global warming and what is being done to deal with this issue.
Scientists have been studying the extent to which the climate has been changed by human activity. All over the world temperatures have been rising.
The current average temperature, which tends to be compared with estimates from the pre-industrial era and the start of the massive burning of fossil fuels, has increased between 0.9 and 1.2 degrees Celsius (1.6 1 2 Fahrenheit) since 1850, in largely due to human activity, according to estimates in the most recent report by the Intergovernmental Panel on Climate Change (IGCC). Most of that warming has occurred since 1975, at a rate of 0.15 to 0.2 degrees Celsius (0.27 to 0.36 Fahrenheit) per decade.
Most people live in areas that have warmed more than the global average, “partly because of urbanization – people are moving to cities, which are ‘urban heating islands’ – and partly because of the growth of the population,” Robinson said. Urban centers, filled with heat-absorbing infrastructure such as roads and buildings, and with fewer trees to provide shade, become “islands” with warmer climates.
Sea levels, which are rising from warming, expanding oceans and melting ice, have also risen more rapidly.
In the 20th century, seas rose about a millimeter (0.06 inches) a year, but that rate has doubled in the last 15 years, according to the most recent data. Waters have risen an average of 8 to 9 inches (21 to 24 centimeters) since 1880, according to estimates, and the IGCC says they will likely rise 17 to 33 inches (43 to 84 centimeters) by 2100.
While global weather and temperatures have fluctuated throughout history, what alarms experts is the speed with which these changes are taking place. Fossil fuels — products of the decomposition of plants and animals deep in the earth — are being extracted at an accelerating rate.
Scientists are beginning to unravel “details about the rate, magnitude and timing of changes” and measure their impact on regions, said Kim Cobb, a climate expert at Brown University.
The planet is already feeling the impact of climate change and measures can be taken to adapt to the new situation and limit the damage. Deaths related to weather disasters tend to decline as people’s forecasts, preparedness and resilience improve, according to scientists.
“The level of damage caused by an extreme weather event is greatly influenced by government policies,” Robinson said. He limited, however, “that adaptation (to changes) has a limit.”
Seth Borenstein contributed to this report.
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