Rearranging the deck chairs on the Titanic
As we celebrate the 100th anniversary of the Titanic disaster, one can reflect the confidence the ship's crew must have had in their ship. Now, just imagine if a group of scientists had been on the ship and had approached the proud captain warning of possible fatal collision with floating icebergs. It is likely that the captain would have politely listened to them but would have just as likely told them all their projections were wrong and they should simply enjoy the trip. I imagine the scientists would have continued to study the trajectories of calving icebergs, estimating the probable distance to impact. Once icebergs were in sight they probably would have contacted the captain again, who would have told them simply that the ship had been built to be "unsinkable". Scientists would have continued to study the bergs, estimating the age of the ice, the likely angle of impact, etc. In the end, the best technology was not up to the task of keeping the boat afloat or all the people alive.
|This figure is from RealClimate.org (Evaluating a 1981 temperature projection - April 2, 2012)|
Today our planet faces a challenge that can affect the survival of many more people and maybe of our species as a whole. For over 30 years, scientists have warned that upcoming climate conditions would likely jeopardize available water resources, agricultural production, human infrastructure hardiness, and human health. The tools scientists built to produce these projections have been much refined since the 1980s but the message remains the same. Human activities are changing the energy balance of the planet causing destabilization of the climate our human species has evolved under. In the 1990s when I was first working on climate change impacts, the historical climate baseline spanned 1961-1990 and the future projections started in 1991. Today one can compare what the general circulation models (also called global climate models in the popular press) predicted for the last two decades to what actually occurred.
Low and behold! James Hansen, adjunct professor in the Department of Earth and Environmental Sciences at Columbia Unviersity, was conservative and global temperature is now above what Hansen's GISS model had projected in 1981. RealClimate.org has published the old figure from the published paper and overlaid observations clearly showing data above the simulation projections (see Figure). Unfortunately, no one seems to pay attention. Climate change deniers and the media, eager to bring controversies and disagreements to their front page, are ignoring the fact that despite all the criticisms climate models have been the target of, and despite all the uncertainties embedded in model structure and emission estimates, the models are right on target. Unfortunately, scientists can only present the facts and it is up to the ship's captain (i.e. policy makers and politicians) to take charge and make a difference in the future of our planet. The stakes are high. This year we will vote for a world leader. We should all ask that leader what his or her next move will be to address the now inevitable changes that our societies will have to face. It is our duty to the world to demand an answer that shows awareness, concern and a realistic plan for action. This is not a rhetorical question. Someone really needs to act now.