Unlike markets, climate won’t bounce back soon
We must make sure we get the fundamentals right
This article first appeared in the Dominion Post, Wellington NZ. December 5, 2008 B5
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The world economy appears to be heading into the worst recession in 60 years. The nominal wealth of global markets has
almost halved in the last couple of months and the United States Government alone is shoring up its banking system with
$US7.6 trillion. Commentators expect conditions will be difficult in the next few years and say we need to get the
fundamentals right.
Severe downturns have happened before and our society has recovered. Each time, confidence and perception of wealth has
grown to exceed tangible assets and credible wealth by a big margin, and the illusion could not be sustained. Each time
we had to go back to the fundamentals.
At same time the global ecosystem has suffered from economic growth and rising population. The United Nation’s
Millennium Ecosystem Assessment of 2005 found that more than 60 percent of the Earth’s ecosystem services were degraded
by overuse and pollution. The importance of ecosystem services to our economic and social well being is now understood
as fundamental, though progress is slow.
On top of this, changes in Earth’s climate are now compounding both economic and ecosystem crises. Estimates based on
our current knowledge of the climate system show Earth is now absorbing more heat from the Sun than it is emitting back
into space. Direct observations of ocean warming to depths of 3 km account for about 60% of the excess - the rest is
warming the surface. This increasing warmth is the fundamental driver behind climate change. The graph shows annual
average global temperature based on measurements from thousands of recording stations around the world over the last 150
years. The increase is only about 0.8ºC, though this figure hides the fact that continents are warming substantially
fast than oceans.
Sceptics say Earth has been cooling since 1998, but this claim rests on the single high value for that year. The scatter
of annual measurements (circles in graph) shows how annual measurements fluctuate due to changes in cloud cover, wind
patterns, ocean upwelling and currents that move heat around the planet in complex patterns. Climate change is only
meaningfully identified from averages over decades. This shows that Earth recently has been warming persistently.
Greenhouse gases have been the subject of scientific research for more than a century. We know that they warm the planet
and, without them, the Earth’s average temperature would be a freezing -18°C. Evidence for rising greenhouse gases
leading to further warming has been reviewed many times over two decades. It is also obvious from melting glaciers and
rising sea levels.
The most comprehensive is the 2007 Assessment of the Intergovernmental Panel on Climate Change (IPCC). This concluded
that our climate is changing largely as a consequence of rising greenhouse gases released by human activities. Both the
observed temperature rise and the patterns it shows are those expected from known physics. Some still insist the sun is
behind the observed warming, but that this cannot explain the lack of change in the past three decades, when temperature
has risen most.
The basic conclusions of the IPCC have now been endorsed by all the major national science academies. We have yet to
agree on solutions, but two simple principles stand out - shifting away from fossil fuels and returning CO2 from the
atmosphere to Earth as fast as possible.
This also makes sense from a geological perspective. The coal, oil and gas that fueled industrial growth accumulated
over hundreds of millions of years at times when Earth had much higher temperatures and 4 to 8 times pre-industrial CO2
levels. We are returning this carbon to the atmosphere in centuries.
If we do not stop carbon emissions rising in the next few years, the consequences will be with us for many generations.
Carbon dioxide, unlike methane, remains in the atmosphere for hundreds of years to heat the earth. Most governments are
now heeding such messages.
As President-elect Obama said last month: “Delay is no longer an option. Denial is no longer an acceptable response. The
stakes are too high. The consequences, too serious “
Governments and communities should now be focussing on getting the fundamentals right for not only the economy but also
climate change. Markets recover in a few years – climate takes millennia.
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Peter Barrett is Professor of Geology and Deputy Director, NZ Climate Change Research Institute at Victoria University
of Wellington. www.victoria.ac.nz/climate-change/.