Post-Copenhagen, we may be heading towards a future in which no comprehensive successor to the Kyoto regime is politically possible. It is therefore crucial that the centre of gravity of decision-making on how we respond to climate change moves towards the sub-national level. The need for such a shift from "top down" to "bottom up" is becoming clearer by the day.
Over the last decade, records of weather and climate trends have revealed larger and more unusual regional and local variations – some unprecedented since the end of the last ice age 10,000 years ago. Among such warning signs are more frequent droughts in wet regions (such as the 2006 drought in Assam, India, previously one of the wettest places in the world) and floods in dry regions (as, recently, the worst floods in 50 years in north-west India).
Such extreme events threaten sustainable development around the world, as natural environments are destroyed irreversibly and economic growth is slowed. Forming loose collaborative networks enables regions, their experts and decision-makers to learn from one another and draw upon national and international resources, including the growing number of consortiums linking major cities, local governments and the private sector.
Experience shows that this "bottom up" approach works very effectively as it is only when smaller areas learn how they will be specifically affected by climate change that widespread, grassroots action can be mobilised.
Although regional variations in climate change are approximately predicted by IPCC global climate models, what is now needed are more local measurements and studies for government, industry and agriculture to better understand their climatic situation and develop adaptive strategies.
Hence, increasing numbers of regional monitoring centres are contributing towards local adaptation plans. Such as in China, where many provinces require targets for power station construction, regional environmental and climate change centres are now well developed.
Experience also shows that local actions can only be truly effective if measurements of climate and environment are widely publicised as well as information about targets, and projections of emissions. Such transparency is needed about what is happening, what is planned and how every individual can be involved – as the Danes show by their community investment in wind power. Localisation of action must be the post-Copenhagen priority if we are to tackle global warming.
• Lord Hunt is visiting professor at Delft University and a former director general of the UK Meteorological Office