Can science predict the future?

In 2009, a 6.3-magnitude earthquake struck L’Aquila, Italy, killing more than 300 people. Six Italian seismologists were later convicted of manslaughter for failing to adequately warn the citizens of L’Aquila of the deadly earthquake. L’Aquila had experienced a series of small tremors in the months leading up to the 6.3-magnitude quake causing the people to wonder whether they should evacuate.

The scientists were not convicted of failing to predict the earthquake but of failing to communicate the risks. But the scientists did communicate the risks accurately to government officials, however it was left to a civil protection official with no specialist knowledge in seismology to communicate this to the general public. His statement to the public was, “The scientific community tells us there is no danger, because there is an ongoing discharge of energy. The situation looks favourable.”

It is debatable whether the seismologists should have stepped in at this point to correct what was an incorrect assessment of the danger. But I don’t believe a charge of manslaughter is warranted in this case.  It seems to me that scientists get vilified when they express the risks and vilified when they don’t.

Climate scientists are vilified by people who have no specialist knowledge in climate science simply because they express the risks of climate change to the public. One of the most vilified of all climate scientists is James Hansen, ex-NASA scientist. To me, James Hansen seems like a nice person. I’ve watched some of his lectures online, seen him interviewed on TV and read some of his papers. As far as I know, he’s never ripped any limbs off puppies or pulled wings off a bird, or abused small children, but some of the disparaging remarks I’ve read about him would leave you wondering whether he has.

Could it be because his predictions have been wildly inaccurate? Even if they had, I don’t believe this is justification for any abuse. At most, it might lead us to give less weight to his findings.

It’s possible to go and read James Hansen’s very first paper on the subject. It’s called Climate Impact of Increasing Atmospheric Carbon Dioxide and was published in 1981. Here’s what he predicts:

It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980’s. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage.

I can’t comment on his prediction of drought-prone regions in North America and Asia (maybe someone else can?), but all his other predictions are happening now. He predicts that the Northwest passage will open sometime in the 21st century. It is looking more and more like it will happen in the early 21st century. He also predicts a rise in temperature of more than 2°C by the end of this century in all scenarios except no growth in fossil fuel usage (from 1980 levels) and coal phaseout. As fossil fuel usage has accelerated since 1981 we are on course to exceed a 2°C warming by the end of this century.

Far from being wildly inaccurate, James Hansen’s very first paper on the subject was remarkably correct. I have come to the conclusion that he is so passionately hated by people who deny the existence of global warming simply because they don’t like what he has to say. Perhaps the public officials of L’Aquila, Italy felt the same way when the risks of a large earthquake were communicated to them and so they chose to edit the warnings before passing them on to the general public.

9 thoughts on “Can science predict the future?

  1. There are very powerful and entrenched forces who have strong economic reasons for maintaining the status quo, and, if anything, the intensity of the fight to discredit Dr. Hansen should be proof of the validity of his research 🙂

  2. That he is subject to such awful characterisations by some makes me think that his predictions are too close for comfort, for some. If climate science was genuinely doing as badly as some claim, then it could simply be ignored as being wildly inaccurate. That the general predictions are starting to become apparent is probably what is driving these attacks on people like James Hansen.

    What worries me a little is that climate science is clearly extremely important. We want talented and capable scientists to be working in this area. I’m concerned that many will just decide that it isn’t worth the effort or the risk and that these attacks will ultimately weaken climate science because talented scientists will choose to work in other areas.

    1. Yes. The climate scientists who have received threats against their family and mysterious packages in the mail containing white powder would surely put people off research in this field.

  3. Rachel,
    I have read carefully my copy of Hansen’ s “Storms of my Grandchildren” and the 1981 paper you reference I am familiar with the apocalyptic views of global warming he has repeatedly championed, over many years.Hansen has a recent summary of his views at the NY Times ,”Game over for the Climate “, Opinion Pages, May 9, 2012.
    Now read Dr. Martin Hoerling of NOAA ‘s point by point rebuttal of a series of baseless claims and statements by Hansen , which he provided to the NY Times in response to Dr. Hansen’ s essay.The rebuttal is at WUWT ,August 13 ,2012. Dr. Hoerling’s rebuttal lists main stream peer reviewed papers ,contradicting claim after claim by Hansen.it is not clear whether the readers of NYTimes were ever informed of Dr. Hoerling’s paper on what he says were his “concerns and objections ” ” on a scientific basis ” to Hansen’ s statements.
    Hansen bears a heavy responsibility as a climate scientist of such note to inform the public accurately ,whatever his views as an activist.

    1. Doug, Martin Hoerling’s response to James Hansen does not address the main consequences of climate change. He only rebuts the prediction for drought-prone and flood-prone regions in the USA. I’m aware that this is a debated issue – as it should be – and that it’s very difficult to predict regional weather in a warmer world. However, he completely ignores the most serious consequences of adding CO2 to the atmosphere and these are: sea level rise and a much warmer climate. Humans cannot tolerate wet bulb temperatures in excess of 35C for extended periods. We were not around when past climates were this hot.

      If two climate scientists with predictions of climate sensitivity at opposite ends of the spectrum (Myles Allen at the lower end and James Hansen at the higher end) think that we need to drastically cut CO2 emissions then I am inclined to agree with them. I’m not sure what Myles Allen’s view on Canada’s tar sands is but he is quoted in this article – http://www.scientificamerican.com/article.cfm?id=tar-sands-and-keystone-xl-pipeline-impact-on-global-warming – as saying we can afford to put one trillion metric tons of carbon into the atmosphere by 2050 and that’s it. At current rates, we will hit that amount in the year 2041. The tar sands contain 240 billion tons of carbon. Both Myles Allen and James Hansen advocate for a carbon tax.

  4. Rachel,
    From Tuesday’s Australian, “Cut and Paste,”
    “As the years roll by,the climate boffins seem to be cooling off on six degrees of warming.
    Sounds as if the Intergovernmental Panel is sure about only a 2C rise now.”-
    1.”Six degrees of warming.The Sydney Morning Herald,May 8, 2001:
    The CSIRO has dramatically increased its projections of the extent of global warming ,suggesting average Australian temperatures could rise as much as six degrees by 2070.”
    2.”The SMH ,December 8 last year:
    According to David Karoly, an atmospheric scientist at Melbourne University and a lead author with the IPCC, global projections may not give a true picture of how we will experience global warming.’ The problem we have is that, even if our best estimate is 4 degrees of warming this century,that is a global average and most of the globe is water,’he
    says.”
    “Four degrees on average means probably three degrees over the oceans ,and five or six degrees on average over the land.”
    3.Roger Bodman and David Karoly on The Conversation site yesterday:(follow publication of Bodman et al 2013):
    “Our recent study has revisited these results….Once we reduced the uncertainty we found there is an increased risk of exceeding a lower temperature change threshold, but a reduced chance of exceeding a high threshold.That is , for business as usual emissions of greenhouse gases, exceeding 6C global warming by 2100 is now unlikely, while exceeding 2C is virtually certain.”
    And The Telegraph (UK),yesterday, 29 May, 2013, ” Tim Yeo: Humans may not be to blame for global warming.”
    “Humans may not be responsible for global warming,according to Tim Yeo,the MP who oversees government policy on climate change.”
    “The Chairman who oversees the Commons Energy and Climate Change Commitee said he accepts the earth’s temperature is increasing but said “natural phases ” may be to blame.
    Such a suggestion sits at odds with the scientific consensus…..Mr Yeo , an environment minister under John Major is one of the Conservative Party’s strongest advocates of radical action to cut carbon emissions.His comments are significant as he was one of the first senior figures to urge the party to take environmental change seriously.
    He said such action is “prudent ” given the threat climate changes poses to living standards worldwide. But ,he said,human action is merely a “possible cause”.”
    Do I detect a trend here?

    1. Tim Yeo has posted a response on his own website. It seems The Telegraph got it wrong – http://www.timyeo.org.uk/news/climate-change-0
      Here’s what he says:

      “In the light of what has appeared on the Telegraph website suggesting that I have changed my views about climate change, I wanted to make clear that this is not the case.

      My views have remained the same for over two decades. I accept the overwhelming scientific evidence that human activities are having a major impact on the climate – there is an overwhelming probability that the impact of greenhouse gas emissions from human actions are contributing to climate change.

      I will continue to press for urgent action on this matter, making the case that the move to a low carbon economy is not just right environmentally but also in our economic interest.”

      Don’t trust what you read in the Telegraph, The Daily Mail or The Australian.

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