We may not have felt it in the United States, but last month was the second-warmest April worldwide since scientists began recording temperature data, according to a preliminary report from NASA.Of course, earlier this week, a NASA press release was ominously titled:
Around the planet, April temperatures averaged 58.5°F, which is 1.3°F above average temperatures. This is only a tad lower than than the warmest April ever recorded, a milestone hit in 2010 when NASA calculated global temperatures of 1.44°F above average, according to the data sheet.
The data announcement also marks this April as the 350th month in a row where the globe has experienced above-average temperatures, a phenomenon that scientists agree is largely caused by increases of man-made greenhouse gases emitted into the atmosphere. Incidentally, April 2014 also marked the first month in human history when average carbon dioxide levels in the atmosphere reached above 400 parts per million.
NASA-UCI Study Indicates Loss of West Antarctic Glaciers Appears Unstoppable
More on this story below the fold.
Joe Romm interviewed the study's lead author, Eric Rignot, of UC Irvine and NASA's Jet Propulsion Laboratory (JPL):
I asked Rignot for his thoughts on whether his study (along with the other) means we should revise the upper estimate for sea level rise this century (and beyond) if we stay on our current in emissions path, which will take us to 4°C (7°F) warming or more by 2100. He replied:With the Center for Naval Analyses Military Advisory Board now finding climate change to be a severe national security risk, perhaps it's time for the world's political and economic leaders to start acting as if this matters.
I think that the minimum will be the upper end of the IPCC projections (90 cm) by 2100 and the maximum is hard to figure out but will likely exceed 1.2 – 1.4 meters.So the upper end of sea level rise will likely exceed 48 to 56 inches! That would not leave “southeastern Florida having many people at the end of this century,” to quote Hal Wanless, chair of the geological sciences department at University of Miami, from a 2013 interview.
The systems we are looking at do not respond to climate forcing in a smooth way, they start slow and then they proceed faster and faster. I am not convinced the numerical models are there yet, they are still conservative and do not include all the feedback, they are getting better than IPCC-class models but still trailing reality quite a bit.
After 2100, it will be several meters from the ice sheets, there is no red button to stop that. I surely hope that by then humanity will have reacted and slowed down the warming. I do not think we want to experience how fast Antarctica could fall apart if we push it hard … as we do now.