While cheering for their faction of scientists, laypeople often lose sight of the big picture — the key things to know when making public policy about this important issue.
(a) The work of the IPCC’s Working Group I (the physical science) and the major science institutes are the best guides for information about these issues.
(b) The world has been warming during the past two centuries, in a succession of warming, cooling, and pauses. As for our influence, here is the consensus of climate scientists (as expressed in the IPCC’s AR5 Working Group I):
“It is extremely likely (95 – 100% certain) that human activities caused more than half of the observed increase in global mean surface temperature from 1951 to 2010.”
Look here for more evidence that this is a consensus. For research about the 1951 date see When did we start global warming? See the surprising answer., 18 October 2012
(c) There is a debate about the attribution (causes) of past warming — which probably varied over time — between natural drivers (e.g., rebound from the Little Ice Age, solar influences) and anthropogenic drivers (eg, CO2, aerosols, land use changes). Other that that stated in (b), the IPCC’s reports make few claims about attribution of climate activity. This remains actively debated in the literature.
(d) Warming of the surface atmosphere paused sometime during 1998-2000. Understanding this is becoming one of the foci of climate science literature, a debate about climate forecasts, both the extent of future CO2 emissions and the net effects of the various natural and anthropogenic drivers.
- Still good news: global temperatures remain stable, at least for now., 14 October 2012
- Scientists explore causes of the pause in warming, perhaps the most important research of the decade, 17 January 2014
- One of the most important questions we face: when will the pause in global warming end?, 25 August 2013
(e) How long the pause lasts might have a large impact on the public policy response to climate change:
- Possible political effects of the pause in global warming, 26 August 2013
(f) Since 2009 my recommendations have been the same about ways to respond to climate change:
- More funding for climate sciences. Many key aspects (e.g., global temperature data collection and analysis) are grossly underfunded.
- A review of the climate forecasting models by a multidisciplinary team of relevant experts who have not been central players in this debate. Include a broader pool than those who have dominated the field, such as geologists, chemists, statisticians and software engineers.
- Run government-funded climate research with tighter standards (e.g., posting of data and methods, review by unaffiliated experts), as we do for biomedical research.
- We should begin a well-funded conversion to non-carbon-based energy sources, for completion by the second half of the 21st century — justified by both environmental and economic reasons (see these posts for details).
- Begin more aggressive efforts to prepare for extreme climate. We’re not prepared for repeat of past extreme weather (e.g., a real hurricane hitting NYC), let alone predictable climate change (e.g., sea levels climbing, as they have for thousands of years).
- A new recommendation — the most important one: break the gridlocked public policy by running a fair test of the climate models.
(g) Posts about preparing for climate change:
- How can we save the world from climate change?
- Preparing for the future: should we be precautionary or proactionary?
- Let’s prepare for past climate instead of bickering about predictions of climate change.
- Climate scientists can restart the climate change debate & win: test the models!