Is it "Game Over" for the Climate?

Our top climate scientist, Dr. James Hansen of NASA, says that it is conceivable that climate stability can be restored if we phase down carbon dioxide emissions from coal over the next few decades and leave unconventional fossil fuels such as tar sands in the ground.  Otherwise, “it is essentially game over” for the climate.

Global carbon dioxide emissions reached a new high of more than 30 billion tons in 2010 prompting Fatih Birol of the International Energy Agency to say that the prospect is getting bleaker. Tragically, the United States and most governments continue business-as-usual with substantial numbers of citizens, politicians, and media in denial.

Dr. Hans Schellnhuber, Director of the Potsdam Institute for Climate Impact Research, says that it is crucial that emissions peak before 2020 to avoid climate catastrophe. This is our critical decade. This year the extent of Arctic sea ice reached a historic low point threatening the Arctic ecosystem and global climates. Sea level is expected to rise a meter or more this century flooding coastal cities, farms, and transportation arteries. Ecologist Peter Sale, author of Our Dying Planet, says that coral reefs will be the first entire ecosystem to disappear from earth in one human generation by 2100, destroyed primarily by ocean warming and acidification. Concern is growing that parts of the Amazon rainforest ecosystem may collapse due to drying, evidenced by the unusual droughts of 2005 and 2010, putting at risk much of life on the planet.

Extreme weather events are largely driven by global warming which causes global air and water circulation to strengthen resulting in dryer and hotter arid areas and wetter wet areas. The American Southwest is experiencing the hottest and driest event on record. Last year Russia lost more than a quarter of its crops due to extreme drought and wildfires and Pakistan suffered extensive flooding resulting in widespread migrations and crop losses. The epic Australian drought, fires, and flooding intensified by global warming have killed hundreds and cost billions.  The extraordinary heatwave of 2003 in Europe killed 35,000.

How hot is too hot? Having warmed 0.8ºC already, the earth is on track to heat up to as much as 6.4ºC above the pre-industrial temperature by 2100.  In 2010 194 countries adopted 2ºC. as a limit, but the climate is already half way between dangerous and catastrophic according to Dr. Schellnhuber. The meltdown of Greenland would occur between 1.5 - 2.5ºC and agricultural production is projected to fall sharply after a 2 - 3ºC rise. 2ºC may be beyond tipping points such as changes in monsoons, biomes, ocean currents, and climatic oscillations. Modeling studies at the National Center for Atmospheric Research indicate that there is only a one in three chance of keeping below 2ºC this century.

Can we get to a safe CO2 level to regain climate stability? Dr. Hansen’s paleoclimatic research informs us that a safe CO2 level for humanity is 350 ppm CO2 or lower. But there is now about 389 ppm in the atmosphere with yearly increases of more than 2 ppm. The probability of staying below 2ºC and returning to 350 ppm this century recedes as nations continue with business-as-usual policies. Dr. Schellnhuber who says that there is a “chance” to solve the problem and Dr. Hansen who says it is “conceivable” leave us with foreboding uncertainty. We must do everything in our personal lives to reduce carbon emissions, prepare for the effects of global warming, and demand immediate action from government.