This is my issue. I can see the disagreement between scientists, and the gap between them and the activists, then read statements like this.
me said:
Well, this is a scientific issue, so I would certainly weight the near-unanimous consensus of climatologists...
It is about time we acknowledged that the political and practical issues are not cut and dried. Reread the above. That is what you are denying.
J
I don't disagree with you here. There certainly is a worrying gap between most activists on a variety of environmental issues and the science they're claiming to defend; climate change is a good example of this. When you see claims that the science is settled, they only mean that the most basic parts of the science on climate change are understood; the exact consequences, the policy implications, and so on are much more nebulous.
It is of course well-known that human releases of greenhouse gases since the Industrial Revolution (with a large acceleration between 1950 and now) have been enormous, have been conclusively attributed to humans, and are absolutely enough to have a large and measurable impact on climate. In particular, the warming observed in the second half of the 20th century simply cannot be explained in any way that does not take into account the massive increase of GHGs due to human emissions.
There is a virtually unanimous consensus that the ongoing rise in GHG emissions is so substantial and rapid that it poses severe risks of a variety of dangerous outcomes ranging from substantial sea-level rise to disruption of ecosystems to large changes in precipitation patterns to markedly increased incidence of heat waves and so on. There's also the risk that "tipping points" will be crossed that amplify these risks: if release of methane from Arctic permafrost and methane clathrates become substantial, global warming will be accelerated; ice sheets are very poorly understood and could be susceptible to sudden changes in melting rates and flow rates toward the ocean resulting in more rapid sea level rise, etc. By their nature, its virtually impossible to quantify these risks.
But when you see somebody using the real risks of climate change to push their specific policy proposal, or when you see activists using single weather events (e.g. Sandy or Katrina) to make some argument, there is often good reason for skepticism about their claims. More generally, the effects of climate change on tropical cyclones, to take one of several examples, are quite poorly understood at present and claims of more and stronger hurricanes should indeed be viewed as dubious at present.
On the other hand, news articles often come out that use real uncertainties to imply that the fundamental facts are themselves in the air, or to claim implicitly that GHG emissions do not have to be (in some way) markedly reduced if we have any desire to mitigate potentially severe impacts from the resulting climate change. This is also misleading at best.
I guess the biggest problem is that most of the general public (including activists, news media, political organizations, and so on) dont think about uncertainty very well. The uncertainties are the interesting part from a scientific perspective, but attempts to communicate the implications of uncertainty dont tend to work well.
Serious question here.
Because of the lack of warming over the last 15 years, there is a search for a heat sink. Has the converse been test? This would be an expiring sink creating the hockey stick rise.
Thats pretty likely to be the case, at least to some extent it is suspected that poorly-understood, decade-scale fluctuations in ocean heat uptake are responsible for a chunk of the acceleration in global warming in the last third or so of the 20th century along with the slow average rise in global temperature averages in the 21st. There was also a cooling phase from the 1940s to 1960s that countered the general warming trend, and another one between about 1900 and 1920. I dont really know ocean heat flows well enough yet to know whats known about what is really going on here, or even to know what is known, TBH. But its certainly likely that the same natural cycles played a large role in both the rapid warming from 1970-1998 and the relative stability since then.
