If you've spent much time reading about the environment during the past few years, then at some point you've heard someone say that you can't link individual weather events to climate change.
Environmentalists say it when climate deniers point to an unusually bad blizzard or ice storm in an effort to refute global warming, and climate-change deniers say it when environmentalists point to extreme weather events such as worse-than-usual hurricanes or wildfires or droughts as evidence of increasing climate disruption.
No matter who is making the claim, they are correct. You can't say with any certainty that a single weather event, no matter how extreme, is a direct effect of climate change.
But you can link climate change to extreme weather trends.
Extreme Weather Linked to Climate Change
In 2010 and the first half of 2011, climate change was responsible for:
- The record-breaking pattern of tornadoes that swept across parts of the American Midwest and South, destroying Joplin, Missouri and killing 536 people by early June, nearly as many U.S. tornado-related deaths as in the previous 10 years.
- The drought in the American southwest that is already worse than the Dust Bowl of the 1930s, which is still considered the worst environmental disaster in U.S. history. As a result of this drought, which has been under way for several years, parts of Texas, Oklahoma and New Mexico are now drier than they've ever been.
- The record snowfall and rainfall in the Rocky Mountains and across the Midwest, which led to record flooding along the Mississippi River. And the huge floods in Australia, New Zealand and Pakistan. Climate-change deniers often point to heavy snow and rain as evidence that global warming doesn't exist, but the link between global warming and increasing snow and rain is inescapable. Warm air holds more water vapor than cold air. So as air temperature rises, we will continue to see a growing trend toward more rain and snow over time.
- The Amazon region has experienced two hundred-year droughts in just five years (one in 2005 and another in 2010), which together have generated enough greenhouse gas emissions from dying trees to cancel out the carbon absorbed by the rainforest in the first decade of the 21st century (about 1.5 billion metric tons of carbon dioxide annually, or 15 billion tons over those 10 years). Scientists estimate that the Amazon will release another 5 billion tons of CO2 over the next few years as the trees killed by the 2010 drought decay. Worse, the Amazon rainforest is no longer absorbing carbon and balancing emissions as it once did, which is expected to accelerate climate change and to leave the planet even more vulnerable to its effects.
How Climate Change is Changing the Weather
There have always been extreme weather events. What's different now is the increasing frequency of so many different kinds of extreme weather.
What we're seeing is not the end result of climate change, but the leading edge of an extreme-weather trend that will continue to worsen if we fail to act.
Although it may seem counterintuitive that climate change can be responsible for opposites in extreme weather, such as drought and floods, climate disruption does create a variety of extreme weather conditions, often in close proximity.
So although individual weather events may be too isolated to link directly to climate change, one thing is certain: if we go on contributing to the problem and refuse to solve it, then the broad effects of climate change are not only predictable but inevitable.