Beyond Zero Emmissions

Service for Peter Castaldo's address on Beyond Zero Emmissions, Melbourne Unitarian Church, Sunday 9th June, 2012

Opening Words

Science fiction author Ray Bradbury died this week. A regular attender and presenter at American Unitarian-Universalist churchers, he was one of the most celebrated writers of speculative fiction, and a recipient of the the Congressional Medal of Honour. Some people (not safe for work) have described him as the 'greatest science fiction writer in history'.

His groundbreaking works include "Fahrenheit 451", a story on censorship which became a film by Jean-Luc Goddard, "The Martian Chronicles", which tempered optimistism of extra-earth colonisation by noting that human failings such as racism, sexism, and class divisions would persist, "The Illustrated Man", "Dandelion Wine", and "Something Wicked This Way Comes".

Ray Bradbury wrote: "Science Fiction is any idea that occurs in the head and doesn’t exist yet, but soon will, and will change everything for everybody, and nothing will ever be the same again. As soon as you have an idea that changes some small part of the world you are writing science fiction. It is always the art of the possible, never the impossible."


The attack on climate science in recent times has been orchestrated, relentless, and effective. Although it has reached fever pitch over the last six months, the campaign has been underway since the mid-1990s when conservative think tanks in the United States teamed up with fossil fuel corporations to develop a strategy to cast doubt on the scientific consensus. As is now well-documented, they consciously adopted the tactics developed by the tobacco companies to prevent or slow down legislative restrictions on smoking.


Unfortunately, the chorus of declarations that the climate scientists got it wrong has had no impact on the earth’s climate. Indeed, those who study the climate itself rather than the bogus debate in the newspapers and the blogosphere understand that climate science and popular perceptions of climate science are diverging rapidly, not least because the news on the former is getting worse.

Let me mention of a number of developments in climate science ... It is evidence that warming is more alarming than previously thought yet which has been buried in the avalanche of confected stories claiming that climate scientists have exaggerated.

• We have just had the warmest decade on record.
• A new study concludes that an average warming of 3-4°C, previously thought to be associated with carbon dioxide concentrations of 500-600 ppmv, is now believed to be associated with concentrations of only 360-420 ppmv, a range that covers the current concentration of 385 ppmv.
• While news reports allege glacial melting has been exaggerated, the best evidence is that the rate of disappearance of glaciers is accelerating.
• The rate of flow into the sea of Greenland and Antarctic glaciers is accelerating, adding to sea-level rise.20 This augments the evidence that cautiousness led the IPCC to significant underestimate the likely extent of sea- level rise in the 21st century. The East Antarctic ice-sheet, previously believed to be stable, has now begun to melt on its coastal fringes.21 The West Antarctic ice-sheet continues its rapid melt.
• Sharply rising temperature in the Arctic have, over the last five years, caused a rapid increase in the amount of methane being emitted from melting permafrost.

So over the last six months, a vast gulf has opened up between the media-stoked perception that the climate science has been exaggerated and the research-driven evidence that the true situation is worse than we thought. Just when we should be urging immediate and deep cuts in global greenhouse gas emissions, the public is being lulled into disbelief by a sustained and politically driven assault on the credibility of climate science.

It is not widely understood that carbon dioxide persists in the atmosphere for centuries, so our future will depend on the total amount we humans put there over the next several decades. On top of past emissions, the total amount depends on two critical factors—the year in which global emissions reach their peak, and how quickly they fall thereafter... et’s make some optimistic assumptions about the peaking year and the rate of subsequent emissions decline and see what the implications are... [L]et’s be optimistic and assume global emissions peak in 2020 and decline by 3% p.a. thereafter, with rich country emissions falling by 6-7%. Where would that leave us? Would it be enough to stabilise the concentration of carbon dioxide in the atmosphere at 450 ppm, the level associated with warming of 2°C? The answer is no. Nor would it be enough even to stabilise at 550 ppm; it would in fact see concentrations reach 650 ppm, a level that translates into 4°C of warming. That’s an average of 4°C across the world. As oceans warm more slowly, an average of 4°C means warming of 5-6°C on land, and even higher closer to the poles.

From the launch for Requiem for a Species: Why We Resist the Truth about Climate Change (2010), Clive Hamilton

Closing Words

For two centuries, since the Age of the Enlightenment, we assumed that whatever the advance of science, whatever the economic development, whatever the increase in human numbers, the world would go on much the same. That was progress. And that was what we wanted.

Now we know that this is no longer true.

We have become more and more aware of the growing imbalance between our species and other species, between population and resources, between humankind and the natural order of which we are part.

In recent years, we have been playing with the conditions of the life we know on the surface of our planet. We have cared too little for our seas, our forests and our land. We have treated the air and the oceans like a dustbin. We have come to realise that man's activities and numbers threaten to upset the biological balance which we have taken for granted and on which human life depends.

We must remember our duty to Nature before it is too late. That duty is constant. It is never completed. It lives on as we breathe. It endures as we eat and sleep, work and rest, as we are born and as we pass away. The duty to Nature ... will weigh on our shoulders for as long as we wish to dwell on a living and thriving planet, and hand it on to our children and theirs.

1990 Nov 6 Margaret Thatcher Speech at 2nd World Climate Conference