Costing climate change - Climate Change: The Facts - page 81

Studies to assess and quantify these concerns include the official ones conducted by large
teams ofexperts. The most prominent ofthese are the UK report byNicholas Stern and the
Australian report by Ross Garnaut. 4 The latter was followed up by other reports, including
the 'Strong Growth Low Pollution' modelling by the Treasury. 5
As authors, this listed 84 Treasury officials in addition to officers from other agencies.
While arguing that 'the analysis should not focus only on narrow measures of income
like GDP', Stern suggested the cost of human induced climate change under
business-as-usual would be 'the equivalent of around a twenty per cent reduction in
consumption per head, now and into the future'. Combatting this, he said, would cost
only one per cent of GDP. Stern received a peerage for the report which Her Majesty's
Government has archived.
Like Stern, Garnaut provided a number of cost estimates, including one of up to twelve
per cent. He maintained 'all of the detailed assessments of the economics of climate
change indicate that the main costs of climate change, and therefore the main benefits of
mitigation, accrue in the twenty-second, twenty-third centuries, and beyond.' 6
Garnaut included many individual features in his warming-induced damage estimates,
though the detailed costs were not well supported. Thus, he argues that the additional
expense for repairing roads and bridges could cost over one percentage point of GDP but
offers no substantiation for these assertions. Oddly, he also argues that other cost increases
will ensue from reduced tourism partly due to a highly implausible collapse of the Great
Barrier Reef but also because of higher electricity costs and a loss of international tourism
(inthereferencecaseinternationaltraveltoAustraliaisprojectedtoincreasesubstantially).
Projectingaseriesof'climaterefugee'scenarios,Garnautalsoseesaneedforincreased
defence spending with an additional cost amounting to 0.2 per cent per annum. However,
the IPCC has now downgraded such fears. In 2005 the IPCC had global warming creating
'50 million “climate refugees” by 2010' (later deferred to 2020). It now says that such
fears, 'are not supported bypast experiences ofresponses to droughts and extreme weather
events and predictions for future migration flows are tentative at best.' 7
Richard Tol has pointed out that the Stern and Garnaut reports were not peer reviewed.
Tol has now been demonised for withdrawing his name as an author of a key IPCC chapter
that he claims the Summary for Policymakers had distorted. That Summary argues, 'the
incompleteestimatesofglobalannualeconomiclossesforadditionaltemperatureincreases
of 2 degrees Celsius are between 0.2 and 2.0 per cent of income … Losses accelerate
with greater warming but few quantitative estimates have been completed for additional
warming around 3 degrees Celsius or above.' 8
TheIPCC'sestimatesofcostsfrominactiontopreventclimatechangeare,nonetheless,
considerably lower than those offered by the British and Australian semi-official
government reports.