Global warming a fact - Christians must act

Dr Mick Pope on climate change and Christians' responsibility to act.

Tens of thousands of Melburnians marched on 27 November ahead of the Paris climate talks.

Tens of thousands of Melburnians marched on 27 November ahead of the Paris climate talks.

By Mick Pope

December 18 2015The role of greenhouse gases in global warming is beyond reasonable doubt, and Christians need to reduce their carbon emissions if they are serious about their discipleship, argues climate scientist Dr Mick Pope.

A letter in the November edition of TMA states that a new study has shown that there is a lot of volatile organic carbon being produced in the oceans, and that this will cool the planet. The letter goes on to claim that the science around the ‘alleged climate threats posed by carbon emissions’ is not settled, and that more research needs to be conducted.

It’s worth understanding that science proceeds step by step. Ideas are put forward and tested over a long period of time. A scientific theory is not a guess, but our best understanding of what is going on. True scepticism is a scientific tool, questioning everything and not being satisfied with easy answers. But neither is it simply throwing out a theory whenever seemingly contradictory evidence appears. We need to be sceptical about that too.

Just like a court case, a good theory is satisfied by multiple lines of evidence. When it comes to climate change, we have over 150 years of direct measurements of temperature. We have 150 years of science that tells us greenhouse gases trap infrared radiation. We have direct (instrument) and indirect (ice cores) observations of these greenhouse gases.

We also have a sceptical eye on this data. Three independent government bodies found that the planet is warming. October was the warmest month in the NASA records. When climate change denialists the Koch brothers funded the Berkeley Earth Surface Temperature project, they were hoping physicist Richard Muller would show it was all wrong. Not only did his team agree with the other temperature records, they also found greenhouse gases were the main driver of the warming. Even Exxon have known this for a long time, and yet played the uncertainty card.

There has never been a theory that disproves that humans are beyond reasonable doubt responsible for warming the planet. Despite uncertainty over the role of the oceans in storing and transporting heat, despite what people have called a warming hiatus, temperature records have continued to be broken.

Despite many lacking details, the models still do a good job, giving us confidence that they will provide a useful guide into the future. The natural effects of volcanoes and changes in the sun are not sufficient to explain the record temperature of the 20th Century.

Every time a new study comes up, it is much overhyped by the denialist machine, conservative newspapers, websites and think tanks. Studies are used out of context or used to say too much. We don’t fully understand the role of volatile organic compounds in climate, but it is not as if studies of aerosols (particles in the air) are new. Studies are carried out all the time on their production, lifetime and role in making clouds, and the work is in progress.

So how should we act? Given that we’ve observed that warming has produced heat waves that have killed thousands, rising sea levels that affect Pacific islanders, droughts implicated in the Arab Spring, and the increased length and severity of the Australian fire weather season, we should take climate change seriously.

Given that the impact of greenhouse gases on global temperature is larger and better understood than any other mechanism, we should act to reduce greenhouse gas emissions.

It’s certainly not the case that every detail of the science is settled. But should we react in a knee jerk fashion to every new discovery that purports to debunk climate change or show it won’t be as serious? No one is rejoicing that our climate is changing, our planet warming and our very way of life under threat. But it is. Better to act on what we are certain of – greenhouse gas emissions need to be reduced – than on what we are uncertain of. How long should we wait?

The precautionary principle is a way of coping with possible risks when our scientific understanding is incomplete. Action on climate change falls well within this philosophy. Given the physics we understand well, the impacts we have observed to date and the likely impacts we face if we don’t act, the current uncertainties aren’t unimportant but they are not significant enough to sit on our hands and wait. In fact, reducing fossil fuel emissions will also have positive impacts on air and water quality, agriculture, and on icons like the Great Barrier Reef, just to name a few.

To not act on fossil fuel emissions would not be scientifically cautious; we already know enough to act. It’s one thing to point out that science is never settled, but it’s sophistry to try to use that to obstruct real change. It might be a coping mechanism in the face of all the bad news, but it’s a maladaptive one. Future generations will judge us poorly if we hide behind uncertainty.

The role of greenhouse gases in climate change is beyond reasonable doubt. Guilty as charged. Christians should pray that Paris is successful in providing some binding agreements. Christians should lobby our government to give up its coal addiction. Christians should be active in reducing their own emissions, not because that will solve the problem in its entirety, but because it will pave the way for larger societal changes, and it’s part of our Christian discipleship to care for the earth. And Christians shouldn’t waste their time looking for holes in climate science, gleefully celebrating some “problem” with it. That’s not a scientific approach and it’s not respecting truth.

Dr Mick Pope has a PhD in tropical climate from Monash University and lectures in meteorology and climate change. He heads up the environment working group for Ethos: EA Centre for Christianity and Society. His book with Claire Dawson, A Climate of Hope: Church and Mission in a Warming World, is available from Urban Neighbours of Hope and online book sellers.