Jan 27, 2011

NASA climate chief: Labor’s targets a ‘recipe for disaster’

NASA climate expert James Hansen says that the Australian government goals of limiting human-made warming to 2 degrees and CO2 to 450 ppm are prescriptions for disaster, writes author David Spratt

When James Hansen talks climate change, people listen. The head of climate studies at NASA, Hansen first gave evidence on the issue to the US Congress in 1988, and is now an eminent scientist and a prominent public advocate. In new research just out, Hansen concludes that at the current temperature, no "cushion" is left to avoid dangerous climate change, and that the Australian government target goals  "... of limiting human-made warming to 2° and CO2 to 450 ppm are prescriptions for disaster". The question Hansen raises is direct and brutal in its implications: is the planet already entering a zone of dangerous climate change? With Arctic sea-ice in a "death spiral", Greenland in 2010 melting at an unprecedented rate, a seemingly extraordinary number of extreme climate events in the past year from the Russian fires to the Pakistan floods, and 18 countries setting temperature records, have we already gone too far for a safe climate? In a draft of a new research paper, Hansen and his collaborator Makiko Sato has opened a new debate about what might be the conditions for a safe climate; that is, one in which  people and nations can continue to live where and as they have been, with secure food production, and in a bio-diverse environment.

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The period of human settlement over the past 10,000 years is known as the Holocene, during which time temperatures and hence sea levels (the two having  a close correspondence) have been remarkable stable.  Temperatures over the period have not been more than 0.5C warmer or cooler than the mid-line (see chart). The warmest part of the Holocene (the "Holocene maximum") was about 8000 years ago, and according to Hansen, today's temperature is about, or slightly above, the Holocene maximum:
"... we conclude that, with the global surface warming of 0.7C between 1880 and 2000, global temperature in year 2000 had returned, at least, to approximately the Holocene maximum."
Note, this is to the year 2000, and temperatures have increased ~0.15C in the last decade, so:
"Global temperature increased 0.5C in the past three decades to a level comparable to the prior Holocene maximum, or a few tenths of a degree higher."

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28 thoughts on “NASA climate chief: Labor’s targets a ‘recipe for disaster’

  1. mattsui

    Yep, we’re screwed……but, hang on a minute, that graph you published has an altered time scale.
    Maybe there’s still hope.
    What we need is a shrill chorus of denial to tell is all one big lie (nazi reference apparently intentional).
    Help us climate denialists, you’re our only hope……

  2. Lorry

    CRAP CRAP and more CRAP.

  3. gregb

    Cue deniar trolls….

  4. Daniel

    but Lorry, you’re a truck, a road vehicle, a cabin with wheels powered by an internal combustion engine! Of course you would think climate change is crap!

  5. PFD311

    Thanks David Spratt for a sensible, worthwhile article about the most important challenge facing us – one that my children will have to deal with, and for which my grandchildren will probably despise people like poor, misguided ‘Lorry’.

  6. joanjett

    Well I’m a parent and hope one day to be a grandparent (if my kids are willing) and I’d prefer to give the head of climate science at NASA the benefit of the doubt on this one. As well as the overwhelming majority of other scientists in the world as well. And the planet.

  7. Ramble

    It is a pity, and of course no surprise, that the entire LHS of the graphs were not shown; instead they have been conveniently truncated at 20k years so as to remove any suggestion that global climatic variability may be totally unrelated to the legacy of Henry Ford and others.

  8. Glen Fergus

    But once substantial melting starts, the loss of heat-reflecting white sea-ice, which is replaced by heat-absorbing dark ocean water, produces an “albedo flip”

    A minor point, but that is not quite what Hanson and Sato mean by “albedo flip” (and have written about before). They’re talking about the effect of shallow summer melt water (and consequent loss of “whiteness”) on the surface of the glacial ice sheets and shelves of Greenland and Antarctica, not loss of sea ice … though they suggest that both may be important.

  9. nadia david

    I went through a range of emotions as I read this….starting with ‘Who the [email protected] lets Andrew Bolt write the crap he spewed forth in today’s SMH?”….then “We’re all going to die in the most awful way….every animal, butterfly, tree, everything we love, it’s all going to die”….then “What’s the point in anything I do? It won’t matter – none of it matters because human beings are just wired to destroy everything for the sake of their comfort.”

    Now, I’m at a low-boiling rage at the sheer stupid, lazy bloody-minded wankers who just want to keep driving their cars, powering their big-screen tvs and air-conditioners and flying their planes. Too narcissistic to change for the sake of everyone.

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