Man is messing up the climate so let's act now

Floods are proof enough that the UK must respond to its change in weather, says Merylyn McKenzie Hedger.

At a recent forum on the south coast, the UK Climate Impacts Programme (UKCIP) and others presented the scientific background to climate change. Later, a local fisherman gave his view. "I don't normally believe scientists," he said, "but something is clearly happening." He went on to list the exotic new species he and his colleagues were finding in their catches: manilla clams, red mullet, spider crabs, even tuna off Cornwall. This was the perfect antidote to dry scientific discussion.

Changes are occurring and people are trying to understand how they affect their livelihood. UKCIP was set up by the government in 1997 to address these concerns. It helps organisations to do their own studies on the impact of climate change.

The severe flooding in southern Britain has brought the issue into even sharper focus. Are these extreme events the first harbinger of the warming trend related to pollution of the atmosphere by greenhouse gases, as most scientists agree?

Recent rainfall is consistent with the predictions made by global climate models for a man-made future climate. The UKCIP national scenarios, derived from the Hadley Centre climate model, show increased autumn and winter rainfall for the region in future decades. Analysis of the empirical evidence from UK meteorological stations by the climate research unit, University of East Anglia, confirms that rainfall episodes are becoming more intense and gale activity is increasing.

It is also evident that changes in practice are required so that new investment (in houses, roads, railways) is more resilient to extreme weather events, and not less.

Although the recent rainfall has been extreme, it has not been exceptional in historical time-scales. What seems also to be happening is that new housing and industrial developments have increasingly urbanised catchments, with impermeable surfaces that give a much faster run-off response. The same has happened in rural areas: the switch in agricultural practice to direct-drilled crops and the use of pipes rather than drainage ditches has also significantly increased the amount of rainwater that can build up.

We need to consider now how to adapt to climate change, instead of waiting to see if the climate models are "right".

Many adaptation strategies can provide "win-win" solutions by increasing our flexibility to cope with the extreme events of the future. An example of such good practice is the use of sustainable urban drainage systems in built-up areas. Other strategies could also be used to reduce risks: both reservoirs and forests can reduce flood peaks, as well as having benefits for water resources and biodiversity. Strategies need to take into account the dynamics of the whole area, rather than isolated sections.

The shoreline management plans promoted by the Ministry of Agriculture, Fisheries and Food, for example, show how a partnership approach with the Environment Agency, local authorities and other stakeholders in areas at risk can create an integrated, sustainable approach to flood and coastal defence.

Admittedly, some forms of adaptation require more detailed climate predictions than we can provide at present. Next year, the Hadley Centre will produce a much more detailed set of climate scenarios for studies in the UKCIP that will go some way to providing this information, but uncertainty will remain.

Surely, this is the most pervasive argument for leaving some climate headroom in our socio-economic systems so that we can respond better to future change.

We can ask awkward questions, encourage a full and balanced debate, request more information, but we need to start to consider now how climate change might affect the infrastructures and organisations we live and work in.

Merylyn McKenzie Hedger is head of the UKCIP (based at the University of Oxford), www.ukcip.org.uk/ukcip.html .

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