Climate and Habitability
06.08.2009 - Atmosphere & Space, Water & Oceans, Land & Geology, Ice & Snow, Flora & Fauna, Human Dimension, Other, Arctic, Antarctic
Scientists from the NASA's Goddard Institute for Space Science (GISS) have been looking into shifts in climate and their consequences for the planet's environment and life. As greenhouse gas emissions and temperatures rise, impacts are being witnessed on physical and biological systems around the world: glaciers and permafrost are melting, lakes and rivers are warming, flowers are blooming earlier, birds are migrating sooner, and plant and animal species are searching for more favourable habitats. And all of these changes ultimately affect humans.
A GISS study published in Nature last year links climate warming to human activity without a doubt. Analyzing more than 29,000 data series of physical and biological systems, the team found that 95% of observed changes in physical systems, such as glaciers, spring river runoff and warming of water bodies, and 90% of changes among plants and animals are linked to human activity. Less than 1% of the data series contained effects that were likely to be caused by something other than climate change.
With climate change affecting ecosystems across the planet, astrobiologists are looking into linking climate change with human activity in order to better understand planetary habitability. NASA's astrobiology program outlines three primary factors needed to sustain life on a given planet: a reliable energy source, liquid water and appropriate conditions for the formation of complex organic molecules. And these factors are directly influenced by the planet's atmosphere, which can either cool or warn the entire planet. Venus, for example, might be habitable if it weren't for its thick blanket of greenhouse gasses.
"Climate change in some ways is an analogy to different environments in space," said Dr. Cynthia Rosenzweig, the study's lead author. "It's really quite amazing. We've only had 0.74°C [change in global surface temperature during the past century], and so many systems are changing. So, while it really does speak to the potential for biological life in very different environments, it also shows how creeping shifts can have dramatic consequences."
