News

Climate change diversity

doi:10.1038/nindia.2010.93 Published online 18 July 2010

Adopting regional measures to combat climate change is more effective than approaching the issue as one global menace with global solutions, a study analysing trends in India and China suggests.

A team of scientists from USA and UK have concluded from simulation models that the amount of intervention required to manage climate change impact differs by region. It will be difficult, therefore, to form consensus on the optimal level of geoengineering needed to stabilize global climate.

Katharine Ricke and M. Granger Morgan from Carnegie Mellon University in USA and Myles R. Allen from the University of Oxford in UK found that solar-radiation management reduces extreme temperature and precipitation for most regions, but it would be difficult to achieve global consensus on the desired level of climate modification.

The scientists simulated climate outcomes and observed what happened if different amounts of reflecting aerosols were to be added to the upper atmosphere as a means of mitigating climate change. They performed a number of climate simulations for 54 scenarios with distinct modifications of the reflectivity of the upper atmosphere.

They could not stabilize the precipitation and temperature parameters simultaneously in China and India despite simulating the same degree of climate modification.

"Our results confirm that solar-radiation management would generally lead to less extreme temperature and precipitation anomalies, compared with unmitigated greenhouse gas emissions. However, they also illustrate that it is physically not feasible to stabilize global precipitation and temperature simultaneously as long as atmospheric greenhouse gas concentrations continue to rise," they say in their paper.

The team mimicked solar-radiation management activites in the model by modifying the natural volcanic forcing inputs. In all, 135 management scenarios were formulated and studied vis-a-vis long-lived greenhouse gases, tropospheric sulphur aerosols and tropospheric ozone.

Temperature and precipitation in large regions such as China and India vary significantly and they diverge from historical baselines in different directions. This is the region why using solar-radiation management might not work to achieve stability in the climate in all regions simultaneously.

"...As our understanding improves, serious issues of regionally diverse impacts and inter-regional equity may further complicate what is already a very challenging problem in risk management and governance," the authors concluded.


References

  1. Ricke, K. L. et al. Regional climate response to solar-radiation Management. Nat. Geosci. doi: 10.1038/NGEO915 (2010)