Dr. Richard S.J. Tol hamburg.de/Wiss/ FB/15/Sustainabili ty/tol.html

Reducing Vulnerability to Climate Change: Development v Mitigation Richard S.J. Tol Hamburg, Vrije and Carnegie Mellon Universities

Reducing Vulnerability to Climate Change Many, most notably Tom Schelling, have argued that greenhouse gas emission reduction is a subsidy to the children and grandchildren of the poor Emissions are concentrated in the rich countries, negative impacts in the poor countries If we want to help the poor, are there not better ways than through emission reduction?

Reducing Vulnerability -2 If we want to help the poor, are there not better ways than through emission reduction? Probably, but the separation of climate change from global change from sustainable development from development has left us empty handed There are, as yet, no models or other tools that tell us that emission reduction will bring us X, tha development aid will bring Y, and that Y>X

Outline Introduction and motivation Actually, I will not answer the question asked (because I do not have a general model of development) but rather wonder whether development reduces vulnerability to climate change more than does mitigation The FUND model Results Discussion

FUND2.4 The Climate Framework for Uncertainty, Negotiation and Distribution (FUND) is an integrated assessment model of climate change; current version is 2.4 It links population, technology, economic activity, emissions, concentrations, climate, sea level, impacts It runs from 1950 to 2200, for 9 major world regions Everything is fairly standard, except the impacts module

FUND2.4: Impacts Agricultural impacts rise and fall with climate, rise with CO2, fall with per capita income Energy impacts rise or fall with climate, fall with per capita income and technology Water impacts rise or fall with climate, fall with per capita income and technology Coastal impacts rise with sea level, fall with per capita income, but coastal wetlands counteract this

FUND2.4: Impacts -2 Cardiovascular and respiratory diseases rise or fall with climate, rise with urbanisation, rise with per capita income (inner city poverty is excluded) Vector-borne diseases rise or fall with climate, fall with per capita income Ecosystem impact rise with climate, rise with per capita income, rise with biodiversity loss How to add this all up?

Trade-offs Estimate the marginal costs of greenhouse gas emissions, that is, the net present value of the difference in damage between two scenarios with slightly different emissions, expressed in $/tC Estimate the marginal benefits of development, that is, the net present value to the difference in damage between two scenarios with slightly different initial incomes, expressed in $/$ Calculate the ratio

Discussion Greenhouse gas emission reduction seems to be a better way of reducing vulnerability to climate change than is accelerating development Note that I used optimistic assumptions on both sides, ignoring trade effects and assuming effective aid The exceptions are the very poor and vector-borne diseases, read malaria in Africa – in that case, development reduces vulnerability faster than does mitigation (while there are other benefits as well)

More Discussion The conclusion seems to be that we should relocate part of the climate budget towards health care in Africa, but not development in general Of course, this has to be tested further – particularly the latter half of the conclusion needs to be assessed with a wider model of development and environment