Planet Earth Online

How to spend $100 billion?

Updated: 11 August 2009

The British Prime Minister Gordon Brown recently proposed establishing a fund of $100 billion, contributed by the wealthiest nations, to help the most vulnerable countries adapt to climate change. This relates directly to the issue of climate equity. Societies with the smallest carbon dioxide 'footprint' often have the least resources to deal with the altered weather patterns caused by human modification of climate.

The work of the climate research scientific community, as summarised for instance in the reports of the UN sponsored Intergovernmental Panel on Climate Change, has over the last twenty years brought the issue of climate change into the public arena. Most politicians, policymakers and environmental researchers agree that should emissions of greenhouse gases (of which the most notable is carbon dioxide) continue at current levels, we are likely to witness unwelcome or even dangerous levels of climate change.

Hence it is appropriate to see the recent associated G8 meeting in Italy discuss an upper limit on acceptable global warming of two degrees since pre-industrial times. However even this level of warming will mean significant environmental change in some parts of the world. It is also recognised that to achieve stabilisation at two degrees of warming will require a massive change in how society generates and uses energy. It is therefore prudent also to plan for the possibility that these changes are not achieved. These considerations lead directly to issues of coping with climate change at which this adaptation fund is targeted.

We welcome this proposal, and want to raise the specific issue of how to make the best use of such expenditure. Climate change is predicted to manifest itself in many different ways. For some locations, direct global temperature increases will alter crop yields, and funds will be needed either to help farmers grow more resilient strains of crops, or to install logistics systems so that food can readily be moved to those who need it most.

Elsewhere, significant increases in atmospheric greenhouse gases are expected to change rainfall patterns, and for some regions this could similarly affect food security and create issues of water scarcity. If storms gain intensity, as is predicted for some regions of the world, then greater levels of flood defences will be needed. A major concern is the huge number of people living in low-lying coastal regions, who could be at the mercy of rising sea levels. For them, funding for improved sea defences will be particularly important.

Wisely planning how the funds generated by the Prime Minister's recent proposal should be invested therefore needs good scientific guidance. In our view, this can be best achieved by climate models providing highly accurate localised predictions. As a result of the significant scientific effort to date, aided by public concern, models simulating climate change have gained considerable skill.

They can now explain many of the large-scale changes that have been observed during recent decades, and this is why their projections for the future can be trusted. But there is still room for improvement, in particular in generating accurate output at much finer geographical resolution than present - this will be required for targeted expenditure for climate adaptation.

Climate models need further enhancement in their depiction of atmospheric processes, determining such things as any altered properties of individual storm tracks, more robust estimates of future monsoon position and timing, cloud formations and interactions with other pollutants such as aerosols. Models must capture all other feedback mechanisms linked to higher levels of greenhouse gases. And such predictions must be translated better into detailed hydrological and ecological assessments of change. We need a step change in the predictive capability of models describing the land surface and crop functioning.

To help us understand all the physical, chemical and biological processes that operate in the Earth system, along with the impact of human activities, we need ever more extensive and novel sets of measurements. The observation of the Earth and its atmosphere from space began many years ago and has great potential to help in this respect. Recent advances in satellite technology suggest that new missions could carry instruments able to verify and actually test climate simulations in ways that have not so far been possible with ground-based observations. On-board sensors are becoming capable of 'seeing' the interactions in global cycles of the Earth system such as the carbon and water cycle.

The UK is very fortunate to have a strong understanding of the climate system. As the Met Office Hadley Centre is our leading centre for climate modelling, there are very tight linkages between climate simulations and the models behind our daily weather forecasts. Indeed, many aspects of the computer code are in common. Hence we can be optimistic that the transfer of information between model formats will yield the needed very high resolution projections of altered 'weather' features around the world. Harnessing advances in emerging computer capabilities will also be essential.

Combined with research from the UK's other environmental research centres and universities, aimed at translating modelled future weather patterns into the issues of most concern (such as food and water availability and flood risk), it should be possible to guide how the funds raised by Gordon Brown's proposal should be spent.

There will be many scientific and technical challenges along the way, but the hope is that simulations of the global environment will be able to maximise the number of people around the world who can adapt to, and be protected from the worst impacts of, global warming.