Urgency on Climate Change

There is no special event triggering this note, just a feeling that the urgency behind climate change action is somehow getting lost.

To start with, there’s one part of the science that everyone needs to know.  Carbon dioxide, the primary factor in climate change, remains in the atmosphere for many decades.   For practical purposes, all the carbon dioxide from burning coal, oil, and gas just adds up.

As a consequence, even with a world really ready to act on climate change, things will continue to get worse through all the years while we try to get fossil fuel usage down to zero.   And it will stay that way for many more decades afterwards.  The commitment has to be made with enough lead time–or it will be too late.

The Paris Agreement was never intended as more than a first step.  At the current stage, the Paris Agreement is effectively a vehicle by which we are getting China and India to stabilize fossil fuel use at a per capita value far below ours–for the benefit of the rest of the world including us.  The following figures give the aggregate and then per capita carbon dioxide production by country.  Note the sharp rise and recent stabilization in China on the first chart and the high US curve on the second.



Current commitments do not get all the way to the Paris Agreement’s goals, but those are only first steps in an ongoing process.  Our exit from the Paris Agreement deliberately undercut the international unanimity that was doing the job for us.

What’s more, for initial steps on climate change, the world and the US in particular have gotten lucky.  The now large-scale production of recently-discovered American natural gas means that we can get a 50% reduction in carbon dioxide production—as compared with coal–without trying very hard.  (Coal is all carbon, so burning it produces just carbon dioxide.  Natural gas is half hydrogen, so half the output is water.  Note that the same logic shows that for climate change there is no such thing as “clean coal”.)

There is in fact an ongoing conversion to natural gas.   Despite our Paris Agreement rhetoric, we don’t have a problem meeting near-term climate goals–much of it is already happening based in part on the price of gas.  But by promoting coal use domestically (and weakening environmental rules for natural gas producers) we insist on creating problems for ourselves and–worse–sending a damaging message to others.  To be clear, natural gas is only a half-step, but it is buying time for renewable sources to be more widely deployed.   The Paris Agreement goals require an ongoing commitment–but not miracles.

The following figure shows our status now.   After many years of increase, global carbon dioxide production has been stabilizing.  However the only year of decrease is still the 2008 crash.s08_FossilFuel_and_Cement_emissions

Scientists have given 2 degrees Centigrade above pre-industrial temperatures as a tipping point, where temperature-related changes become serious and irreversible.  (See here for a good summary of the scientific consensus, here for a blog post on forecasting.)  This is not something to be laughed away.  We are now at 1 degree. The next chart shows that with current fuel consumption (black curve) we will get to 2 degrees in about 20 years, but in that scenario the temperature just keeps rising afterwards. If we want to stay below 2 degrees C, we have to start cutting carbon dioxide production much sooner, about 2020 in the -4% per year scenario. And that means every country in the world has to keep at it every year —hence the importance of unanimity in the Paris Agreement process. Things only stop getting worse when we are essentially done with coal, oil, and gas.


Notice there are no winners and losers with climate change.   Either we stop using fossils fuels or we don’t.  If we do, then we can stabilize the temperature, and it is to everyone’s advantage to keep it under 2 ⁰ C.  If we don’t, then temperatures will continue to rise, and there will be nowhere to hide.

That’s the situation.  There never was any hoax, conspiracy or political game playing—95% of climate scientists worldwide support this.  Try to get that kind of agreement on any subject.  Read this if you want the history.

The bottom line is that climate change is more urgent than we like to think.  It is natural to want to wait and see how bad things will get.  But this is a not a case where that works.  If we wait for symptoms of warming to become our top priority it will be too late.  We will be locked-in as carbon continues to add up, bringing years of increasingly disastrous change.   This is like cancer—first symptoms may be bearable, but if you don’t act now it’s all over.

We need to do everything possible to prepare, and that’s a big job.  We need research both on climate change itself and on everything to do to counteract it.  Industry and government need to prepare for a major transformation, and we need to get back to productive engagement (for our benefit) to finish the job started by the Paris Agreement.

It may be a big job, but it is our role to play, and there is no barrier–other than inaction–to getting it done.

2 thoughts on “Urgency on Climate Change

  1. Pingback: Forecasting Climate Change | on the outside

  2. Pingback: Hurricane Harvey and the Burden of Proof | on the outside

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