Sunday, December 17, 2017

Three Surprises on Climate Change from Economist Michael Grubb - By Lynn Parramore

Two years after the 2015 Paris Agreement, where we stand today is better than you may think 

Michael Grubb, Professor of Energy and Climate Change at University College London and a grantee of the Institute for New Economic Thinking, co-authored a recent study showing that what many saw as an overambitious goal to keep the earth’s temperature from rising more than 1.5 degrees Celsius may actually be reachable.  Climate change deniers quickly pounced, using the hopeful news as an excuse to blame researchers for updating their models and to downplay the climate crisis.  Two years after 195 countries signed the Paris Agreement on climate, Grubb explained what the researchers really found and shared with INET surprising developments on global warming, the future of nuclear energy, and why the rest of the climate community isn’t too worried about President Trump.

Alternative Energy Wind (Credit: Click to Enlarge.
Lynn Parramore:  Let’s talk about the recent study you co-authored that created a media stir. You found that things might be a little better than we thought in terms of the Earth’s temperature rising.  Can you explain your conclusions and how they have been spun in the press?

Michael Grubb:  Sure.  It turns out that we had a longer period than expected where temperatures didn’t rise as fast as the trend of the previous few decades – though they have jumped in the past couple of years.  So we updated estimates that were almost a decade old.  I do want to emphasize that the difference between what we found and what was widely understood from previous research is small— it shouldn’t have been a massive deal.

Our study in no way means that we don’t have a climate crisis.  But we might be slightly better positioned to meet certain goals, like those set forth in the 2015 Paris Agreement, than we thought.

LP:  And yet Breitbart and other media outlets shouted that climate scientists “admit they were wrong about global warming.”  How do you respond to that?  How can scientists combat the misinformation?

MG:  Partly it’s a problem of scientists not communicating effectively what they do.  They run big, complicated models, and measure the past.  Scientists looked at C02 emissions since the Industrial Revolution and made projections based on their findings:  For every billion tons of carbon we dump into the atmosphere, the temperature goes up by a certain amount.

Based on those assessments, the people who had been running the big modeling projections, said, ok, if we want to prevent the global temperature from rising more than 1.5 degrees Celsius, then we can have only have so much in emissions—and it looks like we’ve only got a few years left at current emission rates before we pass the limit.

Governments made a deal in Paris based on ‘avoiding dangerous interference’ with the climate system, which included this target of 1.5 degrees Celsius at the ambitious end.  A lot of people, including me, were pessimistic about achieving that goal.

The studies had actually presented estimates on temperatures rising within a range, but unfortunately, some in the scientific community succumbed to the demand for a single number.  So they chose a number in the middle of the range that the models showed.  Where we are today is actually well within the range of the models.  We’re just not right in the middle.  We have additional information about what’s happened since then and we have slightly different estimates of the way gases other than CO2 contribute to rising temperatures.

LP:  So it’s not that scientists got anything wrong.  Rather, it’s a matter of previous findings becoming oversimplified in the public discussion and of more information coming to light since then.

MG:  Right.  Unfortunately, a lot of misleading things have come out in the press, especially Breitbart, which got it all wrong.  But this is the basic challenge for science.  If you really look at what’s happened in relation to this paper, you see that science is about continually trying to improve your estimates.  The political approach being adopted, in contrast, is to say that any attempt to improve anything in your estimation is treated as, “Oh, well, it was all wrong before then!”

How is knowledge supposed to advance if you never improve on what you did before?  There’s also a huge challenge about how to effectively communicate uncertainty and complexity.

LP:  You actually once stated that the Paris goal of 1.5 degrees Celsius was “incompatible with democracy.”

MG:  I did!  That was actually my first tweet ever.

LP:  That was a doozy.  Has anything else happened since that tweet to change your mind?

MG:  Yes it has!  I was responding to the notion held by many that we could reach the goal technologically if we spent enough quickly enough.  Well, of course!  But the problem is a political one.  It’s a social science problem.  Instead of social scientists in this space, we have modelers churning out models with targeted carbon prices and so on, when in reality we can’t get even a small part of it through a political system.

So that tweet was my cri de coeur to say, look, this goal is impossibly ambitious in real countries where people vote and may well object to what we’d have to do.  So you’d better start thinking about the social scientific aspects.

Three things have changed since the tweet.  First, we now have an approach that indicates we may have about 20 years of current emissions before we blow the 1.5 degree Celsius goal – meaning for example, if we reduce in a slight line from today for 40 years we might do it.  Second, to everyone’s surprise, Chinese emissions have stopped growing for the previous two years, and global emissions stopped growing, too.  I don’t know if that’s enduring, but it looks like China has shifted and that’s a fantastic development.  The third thing is that the cost of renewables has collapsed faster than expected.

Read more at Three Surprises on Climate Change from Economist Michael Grubb

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