Climate Change: Innocent Until Proven Guilty

The trial on global warming is reaching its climax. Climate change is perpetually featured in the news, from UN summits in Paris to climate deniers in the Senate.

The Earth’s temperature is increasing; that fact is not up for debate. But what’s causing climate change? How much will the temperature increase by? Who will it affect? What will happen to islands and coasts? Those are the questions that constantly rotate in the climate debate.

Unfortunately, our society is locked in a cycle where focus is on specific details that don’t always add up when looking at the bigger picture. Debating whether climate change is caused by humankind or is a natural progression doesn’t address the fact that the climate is warming.

Will we ever finally emerge from this stalemate?

Plaintiff: Scientists.

Defendant: Climate change.

Jury: Politicians.

Verdict? Debatable.

All eyes are on the defendant standing in court. The plaintiff has set out the facts. The scientific consensus is that the planet is warming. We have surpassed 400ppm of carbon dioxide in the atmosphere, which hasn’t happened in more than 23 million years.

Now it’s time for the jury of politicians to weigh in.

Policy decisions require evidence to support legislation. Because climate change is happening in real-time, the data used stems from historical records and climate models. Climate models are needed on top of historical and real-time data because of the time lag between carbon dioxide emissions and the effect on climate. It takes 40 years for the accumulated carbon dioxide to affect global temperatures and climate, so we need climate models that estimate the effect of current emission levels on the future.

These models simulate the climate system by incorporating variables such as radiation, air movement, cloud formation and precipitation into equations that generate the interactions and feedback loops that shape our climate. Several key assumptions go into these calculations, so modelers must test the variability and margin of error in each model.

It is those margins of error that are in contention in the political world and are used as ammunition to question the accuracy of climate modeling. While there is variation in results, most models are consistent in their findings and the conclusions are the same. There are, however, a couple of data sets, especially one stemming from the University of Alabama, that are outliers and conclude that the earth will not warm as much as predicted.

Until recently, politicians used the data from the University of Alabama as evidence that the government doesn’t need to take strong action on climate change. However, a study was recently published by researchers at the University of Washington that explores the sources of error in satellite temperature records, which are used as an input in all climate models.

This latest study examines the role of satellite orbit drifts, which influence the diurnal temperature variation and may affect the calculated temperatures that are used as inputs in climate models. The study offers a calibration scheme to address this common issue amongst all satellite data and unify results across organizations. From the results, the researchers identify the findings from the University of Alabama as outliers, questioning whether satellite orbit drifts affected the data.

It is not unusual for politicians to choose data sets that support their political position; it is a universal phenomenon. However, the manner in which data from sources such as climate models is handled varies across countries. Climate models and historical records are treated differently according to the decision-making process of the region.

The European Union, for example, clearly states in the Maastricht Treaty, which created the EU in the early 1990s, that environmental policy will be formulated based on the precautionary principle. The precautionary principle focuses on action to “prevent or refrain from contributing to possible serious irreversible harm to health and the environment- whether on an individual basis or in terms of widespread environmental and health consequences.”

In contrast, the US government does not operate on the precautionary principle, and instead chooses to wait until there is strong supporting scientific evidence of “significant risk of harm,” a theory similar to “innocent until proven guilty.” In a state that typically uses a cost-benefit analysis as a decision-making framework, arguments for uncertain outcomes always fall short.

Policymaking is not black and white. There isn’t a universally perfect method to run a country and make political decisions. That being said, politicians should include risk in their assessments. Understanding and managing the uncertainties related to catastrophic risks is critical.

A detailed cost-benefit analysis favors the quantifiable factors we can see today. The costs of imposing environmental regulations are clear, while the future benefits are both intangible and unquantifiable. How does one put a dollar value on the benefit of avoiding ocean acidification?

It’s convenient to think in terms of today, but we have to be thinking about the risks of tomorrow.

The climate models are clear. The evidence exists. The judgment has been made. Climate change is happening.


Instead of appealing to prove innocence by nitpicking the outliers in climate models, why not accept the verdict and start acting to mitigate the damage?

Written by Eleni Polychroniadou

Originally posted on the Antenna blog:

Published by elenipolychroniadou

Cynical idealist. Passionate about catalysing global change.

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