Climate change panel reports global warming is ‘unequivocal’
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Just as it seems readily apparent to most of us when we stick our noses out the door, the warming of the planet’s climate system is “unequivocal.” This is according to the over 1000 scientists of the UN’s Intergovernmen tal Panel on Climate Change (IPCC), who re leased the first part of their Fifth Assessment on Sept. 27, in Stockholm. The “Summary for Policymakers” states that each of the last three decades has been successively warmer on Earth’s surface than any preceding decade since 1850, and the human influence on ris ing temperature due to fossil-fuel combustion is clear.
Using the term “extremely likely,” the sci entific body is 95% certain that the warming is anthropogenic, as compared with a 90% “very likely” in its 2007 report, and only 66% “likely” in 2001’s report. This is because the evidence is more firmly established than ever, coming from 9200 peer-reviewed stud ies, two-thirds of which were published after 2007.
Little has changed since the first assessment of 1990, so we may ask what good this great search for answers on the part of the UN is when nothing has been done to preserve the climate from rampant destruction thus far. In 2012, carbon dioxide emissions were at a re cord high and rose 1.4% to 31.6 billion tons. In May of this year, seasonal CO2 concentrations in the Northern Hemisphere reached 400 parts per million for the first time. Their rate of increase has accelerated since the last century, and it is now at 2 ppm per year.
Thirty percent of our carbon dioxide emissions have been absorbed by the ocean, causing it to acidify and imperil marine life. The IPCC expects acidification to increase and amplify warming by 0.9F because of the restricted ability of the ocean to take up more carbon. Another important observation the report makes is the eventual thawing of the permafrost down through the top 10 feet, which would release twice as much carbon into the atmosphere. It behooves everyone to pay atten tion to these and other dangerous feedbacks at work.
Critics often accuse the IPCC of being conservative. This is because of its consensus-based way of drawing conclusions, the undue influence government leaders and environment ministers have on decision making, and the unwillingness of any scientist to be absolute ly 100% sure about anything given the gaps in human knowledge. Nonetheless, the IPCC has strengthened its general conclusions: Climate change is indisputably real, caused by humans, and proceeding unabated. The overwhelming evidence is found in warming oceans, vanishing ice masses, rising sea levels, and raging weather extremes due to unrelenting fossil-fuel emis sions.
However, some scientists fear that pressure from skeptics may have forced the panel to “low-ball” some of its predictions on sea-level rise and climate sensitiv ity—the projected effect a doubling of CO2 over preindustrial levels would have on global temperature if business proceeds as usual. Their new sea-level rise projection is 28 to 97 cm by 2100, which is 50% higher than the old one, but many glaciologists expect a one meter rise (39 inches) by then. Future IPCC tempera ture ranges from 1.5 to 4.5 Celsius (3-8 F), with a dou bling of CO2.
On the other hand, climatologists such as Michael Mann at Penn State believe the low-end effect of dou bling CO2 should be 2C. The people of island nations threatened with inundation by rising seas prefer there be no greater than a one-degree rise, but they have little say in the matter since it would appear that the Carbon Barons are hell bent on allowing the situation to play out to the nightmarish doubling scenario.
Whether sea levels and temperatures rise to great extremes, things are already bad enough, and we must stop spewing greenhouse gases into the atmosphere immediately lest they get any worse. Depending upon 12 SOCIALIST ACTION OCTOBER 2013 when there was an intense El Nino. Beginning instead with 1999 or 2000 yields a more upward-pointing curve because every year after 2000 has been warmer.
From a statistical point of view, it is still the case that the 10 hottest years on record have occurred within the last 14 years, and they occurred during major cooling factors. Because climate is weather averaged out over multiple decades, centuries, and millennia, looking at an isolated 15-year time span can be misleading and not truly reflective of actual trends.
Also to consider are the natural variables that can turn down the temperature dial—volcanic eruptions, the solar cycle, and the El Nino Southern Oscillation (ENSO) when it is in a La Nina phase. Since 1998, there have been a series of medium-sized volcanic eruptions in the Pacific region that have ejected volcanic ash into the atmosphere and reflected incoming solar radiation back out to space.
In addition, an unusually long solar minimum oc curred from 2005 to 2010. Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research believes that the transition from the solar maximum to mini mum probably contributed as much as a 15% decrease in planetary heat absorption. Yet, despite the volcanism and a reduction in solar insolation, the planet managed to warm.
ENSO is one of the major engines that drives the world’s climate. It consists of an El Nino phase with warm Eastern Pacific Ocean surface waters and the release of heat into the atmosphere, often with a ten dency to shed moisture over the ocean. Its counterpart is the La Nina phase, with cold surface waters and the absorption of heat with a tendency to shed moisture over land in some areas.
There have been a cluster of La Ninas in the last de cade, (5 LNs compared with 4 ENs). Even so, both El Nino and La Nina years were warmer overall from 1950 to 2010. Therefore, the noise associated with natural variation does not mean a change in the signal of global warming. Climatologists believe that the next El Nino could produce a new global mean temperature record because of all the heat the oceans are absorbing.
Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the heat accumulated between 1971 and 2010, according to the IPCC. This is because the atmosphere holds only 2%, and the land is a poor heat conductor, absorbing slowly. The ocean is thermally stratified. The upper layer—the top 700 meters—holds two-thirds (continued on page 9, in “A socialist for Minneapolis city council”)