Even if it were possible to maintain greenhouse gas emissions at today's levels, there is already sufficient CO² in the atmosphere to ensure that the world will experience some degree of warming.   It is increasingly apparent that mankind will have to adapt to a changing climate. Quite how extensive this adaptation will need to be is going to depend on how successful we are in reducing our carbon dependency.  But some indication of the problems that may lie ahead can be seen the the social and economic impacts of extreme weather events.  In the future, flooding of low lying areas will have a substantial impact on land usage, reducing the potential for habitation and incurring high capital costs for flood defences.  Agricultural land may no longer be viable where temperatures rise substantially or rainfall becomes too frequent, leading to potential food shortages.  And populations in many countries will have to learn to live with a less hospitable climate raising the likelihood of large scale migration from the worst effected areas.  The cost of all this adaptation will have a substantial impact on the global economy, with estimates ranging from $15 to $150 billion annually for building and infrastructure alone. This wide range reflects the uncertainty that underlies international efforts at CO² mitigation. 

 While adaptation poses significant problems for the industrialised economies, it is in the developing world where the real impacts will be felt.  Countries who have done little to contribute to global warming, are likely to find themselves experiencing some of the worst effects, while lacking the funds required to adapt.  In recognition of the gravity of this situation, the international community has acknowledged its obligation to support these countries and the G8 summit at Gleneagles committed to double aid flows by 2010.  Alongside this financial aid, the most effected countries will require a wide range of assistance including  adaptation of infrastructure, the transfer of low carbon technologies, development of drought resistant crops and practical help with healthcare.  The importance given to assisting the poorest countries to adapt to climate change reflects the growing recognition of collective responsibility in combating this global problem.