Wednesday, March 20, 2013

The art of empty rhetoric

Op-eds on scientific issues are perhaps the single biggest disgrace to the world of journalism. Science is not open to opinion. There is certainly freedom to interpret the bounds of uncertainty given a particular analysis, but this is by no means equivalent to the rhetoric used in a typical op-ed. Climate change continues to be the most classic case of what happens when the two worlds of science and opinion collide.

I've already written too many posts on this as it stands, but everytime I see a major news source publish propaganda like this Op-Ed by James Taylor, my frustration is ignited anew. In it, James repeats the latest popular refrain that global average temperatures haven't changed since 1995 while CO2 continues to climb. Never mind that there is already a fantastic website where you can pick any time interval you like to draw a trendline using real climate data and show any range of warming, flat, or even cooling trend you fancy, it is the climate system as a whole that really matters.

Ever since the hockey stick controversy, climate change deniers have narrowly focused on changing this single narrative, while ignoring the massive changes underway across the whole system of our planet. Permanent ice loss, CO2 acidification of the oceans, permafrost melt, and vegetative migration are just a few of the systemic changes taking place right now, and each on its own poses huge risks for catastrophic impacts on both our environment and our economy.

Given that global average surface temperatures have not changed much in recent years, is it possible that something else in the great system of the earth is giving us a temporary reprieve?  Perhaps we are just melting the ice in the cooler? Sure we have a pretty big cooler and all, but what happens when that ice supply disappears? How much energy has it been offsetting?

So for fun, here's a back of the envelope calculation of what happens when you melt 4,260 metric gigatons of ice between Greenland and Antarctica from 1992 to 2011. Given the enthalpy of fusion alone (so disregarding any warming of sub-zero ice), it takes 333.55 kJ for 1 kg of ice to melt. This means that 1.4×1021 Joules have been absorbed over a period that is just a few years longer than our period of supposedly flat temperature change. To put this in perspective, this is like shutting the sun off for the entire planet for 139 minutes. To put that further in perspective, given that March is the equinox and looking at the average daily temperature change (with equal parts sun and night) in a relatively clear sky, mid-latitude region like Fort Worth, TX, we see a mean of about .56 degree Celsius change per hour. So, if all of this adds up, just part of the ice that has been melting in our global cooler has helped offset roughly 1.3° C in change over the last nineteen years. For those so inclined, here is a spreadsheet walking through the conversion.

Now it's highly unlikely that permanent ice loss alone has prevented 1.3° C in warming. Most early reviewers of this post suggested that relative to the total energy at play in the earth's heat exchange with the sun and space, even such massive numbers as 1.4 zettaJoules may disappear in the wash. Yet another recent article examining deep ocean temperatures suggests that heat-sinks like the deep ocean and permanent ice loss are likely having an impact on balancing surface temperatures in the midst of accelerating warming. With some additional back of the envelope calculations on the volume of seawater, I'm sure we could hit magnitudes on par with the total energy cycle of the earth. 

A temperature change of 1.3° C might not seem like much, but in reality we are trying to prevent a further 1.5° C change, after which the risks for catastrophic impacts to our planet and economy begin to skyrocket. Are these deniers really so short sighted that they are willing to bet it all just so we can continue using a finite resource that will ultimately run out anyway?  Don't we need innovation right now? Are we really going to let ourselves be paralyzed from action just because a powerful industry mongers the threat of a rise in short term energy costs when it is just as likely to bring energy costs down in the long term? Are we really going to let ourselves be held hostage by a single industry, again?

Instead of using this temporary and perfectly explainable reprieve to try and deny the entire system of climate change, we should be making the most of this opportunity to try and avoid the worst of the risks. For more on  the trade-offs of delaying action and the impacts on risk, check out this simple model where you can explore different strategies for yourself.

For a truly in-depth look at how the earth as a whole is changing watch the following NOVA series in its entirety. It's not only a great testament to the scale and complexity of our planet, but also to mankind's ability to measure and understand it. It this level of innovation that an organization like NASA delivers that we so desperately need. If we can build an Apollo program back in the 60's when technology was really just in its infancy, how many Apollo scale programs could we do right now to take on all the of the problems in front of us? We have the tools. All we lack, is the courage and the strength to break free from this collective state of apathy we find ourselves in today.

Watch Earth from Space on PBS. See more from NOVA.