Nature Conservancy Magazine: Summer 2007

Ever wondered how much you’re contributing to climate change? Find out how your actions stack up and learn how you can reduce your “climate footprint” through easy steps such as recycling, telecommuting and turning down the thermostat.

Go Deeper

The Consequences of Climate Change
Which will have the most impact on your life, or on the places you care about?

What We Are Doing
Helping threatened ecosystems adapt to climate change.

An Unequivocal Change

Monumental Report Leaves Little Doubt that Humans Have Hand in Climate Change

The world’s leading body of climate scientists concluded in its latest assessment that climate change is “unequivocal” and that people are more than 90 percent likely to be causing the recent increases in temperature and other climate shifts, such as fiercer hurricanes and heavier rainfalls.

The multivolume report—an extensive survey of climate data and research that was vetted by more than 100 of the member governments of the Intergovernmental Panel on Climate Change (IPCC)—represents the culmination of six years of effort by several hundred scientists.

Scientists have tracked an increase in global temperatures since 1906 of 1.3 degrees Fahrenheit, and the IPCC projects that temperatures will rise by 3 to 7 degrees Fahrenheit by 2100. “Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations,” concludes the report’s first volume.

The report documents how climate change has already affected every continent and lays out six scenarios that project how Earth will continue to change, depending on efforts to reduce emissions of heat-trapping carbon dioxide and other greenhouse gases.

If these emissions continue unabated during the next 100 years, the scientists project that consequences will include a rise in sea level that could flood or erode major coastal areas; an increase in wildfires that could destroy forests and significantly increase the range of savanna and grasslands; and an increase in heat waves, storms and droughts.

The report also warns that if emissions are not reduced, up to one-third of the world’s species could face extinction. Other impacts may include altered migration patterns, especially for birds, and the poleward shift of species such as plankton and trout in search of colder waters.

Climate change is also likely to require changes in how conservation groups work. “We have already observed that climate change has drastically shifted forests, grasslands and other vegetation at sites around the world,” says Patrick Gonzalez, a Nature Conservancy climate scientist and expert reviewer for the IPCC report. “We are analyzing potential future vegetation shifts to change how and where we work, so that we can improve the ability of ecosystems to cope with warmer temperatures and other impacts of climate change.”

For example, the Conservancy’s Florida Reef Resilience Program has identified corals in the Florida Keys that are heat resistant and plans to transplant these corals to help restore damaged areas.

The report concludes that strength and swiftness of reduction strategies will determine what is left of Earth’s vulnerable regions a century from now. With Arctic summer sea ice already decreasing by as much as 7 percent per decade, our window of opportunity may be melting away.

—Jennifer Winger

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