The reasons the IPCC report is actually a conservative, best-case analysis are:
- The IPCC requires information to be submitted years early, so the latest science is not included.
- Because of the growth of China and India, the actual worldwide emissions of CO2 in the past few years have been higher than the worst case assumptions of the IPCC.
- The IPCC tended to use linear models since they are easier to build and analyze, but the world doesn’t actually work that way. Consider H2O. When it’s colder than 0ºC (32ºF) it’s ice, when it’s warmer than that, it’s water. It doesn’t slowly transition from ice to water as the temperature increases; the change is abrupt.
- The IPCC did not include “carbon feedback” mechanisms in its analyses for the most part because they did not know how to model them at the time. These feedback mechanisms create “tipping points” that take control of climate change out of our hands. Not only are tipping points possible, we are getting close to some... perhaps only years away. See further discussion of tipping points below.
- The IPCC includes many scientists and others who represent the interests of their countries. It’s consensus process tends to eliminate the more dramatic findings, even though many climate scientists believe that some of the more dramatic outcomes are not only possible, but likely. Recently, more climate scientists have been speaking out about how climate change is likely to be much worse than the IPCC has predicted.
When you correct for the items above, the news is not good. It is likely that climate change will be much worse, much sooner than most people think. All of the climate change effects we have seen so far, including the rapid disappearance of Arctic sea ice in the summer — a phenomenon you could observe from the Moon — and the increase in extreme weather have all happened with just a 0.8ºC global average increase in temperature. While the conservative IPCC report predicts a global average temperature increase of 2ºC to 5ºC by 2100, the actual increase, if we continue on the path we are on, will be 6ºC or higher.
Climate scientists generally agree that to avoid catastrophe we better keep the temperature increase below 2ºC. A 2ºC warming will be really bad and a 3ºC warming will be biblical. At 4ºC and beyond, we could face the collapse of agriculture, the economy, and even civilization itself. And because of tipping points, a 1ºC warming can lead to a 2ºC warming which can lead to a 3ºC warming and so on. Some of the nearer-term tipping points we need to worry about are:
- While the world has only warmed 0.8ºC on average, the warming is more pronounced at the poles and this has led to significant warming — and melting — of the permafrost, which is essentially frozen peat. When the permafrost melts, its organic material decays and gives off CO2 or, if the peat decays in water, methane. Methane is 21 times more powerful as a greenhouse gas compared to CO2. The permafrost contains as much CO2 as the entire atmosphere holds. Once the permafrost begins giving off greenhouse gases a rate faster than we can decrease our greenhouse gas emissions, its Game Over.
- There are vast amounts of frozen methane stored in ice structures under the oceans. Much of this frozen methane (called clathrates or hydrates) is deep in the ocean where they won’t be affected much by the surface warming of the ocean caused by global warming. However, some of the clathrates are located in more shallow waters of the Arctic Ocean where the recent dramatic melting of the summer sea ice could cause significant amounts of this frozen methane to be released. In 2008, it was possible to circumnavigate the Arctic Ocean for the first time in recorded history and research ships in the area noticed places where methane were bubbling out of the sea.
- Global warming is causing vast amounts of trees to die through drought, beetle infestation, or other means. The dead trees give off CO2 when they decay or burn in wildfires — which have dramatically increased in the past decades. When trees decay or burn, they give off CO2 which leads to more warming.
- The oceans absorb much of the excess CO2 that mankind has released into the atmosphere. But as the ocean warms and as it becomes more acidic (from absorbing our CO2) its ability to absorb CO2 decreases. This effect is already being observed and it means that we need to decrease our emissions faster than it might otherwise seem. The higher acidity also makes it harder for ocean animals to form shells and this is also being observed and is expected to become much worse this century. The oceans can reach a point where they begin releasing CO2 into the atmosphere and that is also Game Over.
The time to take dramatic action is right now. We need to put a price on CO2 and other greenhouse gases through a “Cap and Trade” system or tax. We need to ban new coal plants and phase out existing coal plants (which are the worst CO2 offenders). We need to mandate energy efficiency and renewable energy and stop subsidizing fossil fuels. We need to phase out traditional beef production (which creates as much greenhouse warming as cars do!). And we better agree on a serious follow-on to the Kyoto Protocol this December at the COP15 meeting in Copenhagen.
Based on my discussions with some climate scientists, I believe that it may already be too late to avoid catastrophe by only reducing greenhouse gas emissions. While we must quickly and dramatically lower our CO2 emissions, we also need to research geo-engineering approaches that attempt to artificially remove CO2 from the atmosphere or reduce warming by blocking some of the sunlight that reaches Earth. Like chemotherapy, some of these approaches have bad side affects, but also like chemotherapy, the alternative to treatment might not be acceptable. Geo-engineering solutions that focus on removing CO2 from the atmosphere, rather than those focused on blocking sunlight, are probably safer. We should invest a lot of money now on researching various geo-engineering approaches to see which might work while minimizing the bad side effects.
Humans respond best to threats that are immediate, visible, simple, personal, have historical precedent, and are caused by another “tribe” (think Al-Qaeda). Unfortunately, climate change, has none of these characteristics and this may partially explain why so little is being done to address the biggest threat mankind has ever faced.
It’s also human nature to be optimistic. But things don’t always work out for the better. And in this case, the stakes are too high and scientists tell us that there is no reason to be optimistic if we don’t take serious action right now. For the sake of our children and grandchildren, let’s get moving.
You can find further information on my web site: Climate Place
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