New paper: Wild card of decadal variability when simulating future climate scenarios

What follows is the first half of a post written by IRI climate scientist Arthur Greene for the CGIAR Research Program on Climate Change, Agriculture and Food Security web site. Greene describes his work to understand how year-to-year and decadal climate fluctuations can act to either enhance or mitigate the effects of climate change. Follow the link at the bottom to read the full post.

Climate variability means the fluctuations in rainfall, temperature or other attributes that make one year – or one decade – different from the next.

So then, how large are the fluctuations (variability) in rainfall and temperature that make up one year? More to the point, how do these fluctuations compare with the changes we might expect from global warming?

The answer to this question depends on where, on planet Earth, one stands: In theWest African Sahel in the mid-20th century, rainfall experienced a decade-on-decade decrease that was quite large. This can be compared with any slowly-evolving trend we might associate with global warming. Across the continent in equatorial East Africa, however, decade-to-decade variations were muted.

In a recently released Working Paper from the CGIAR Research Program on Climate Change, Agriculture and Food Secuirty (CCAFS) series, we looked at the simulation of near-term climate change at target sites in Kaffrine, Senegal, and Machakos in Kenya. Our paper focuses primarily on the methodology of simulation and the generation of simulation data.

As we look to the future, global climate models can help us to understand the warmer world in which tomorrow’s crops will be grown. Observations based on weather station records on the other hand, can provide insights into the nature of regional climate variability.

Thumbnail_SimulationIn our Working Paper, “Simulation of near-term climate change at target sites in West and East Africa” these complementary sources of information have beencombined while producing future scenarios for 2050 .The simulations incorporate both climatic changes and the decade-to-decade variations that may act to either enhance or mitigate the effects of climate change….

…The simulations are intended to drive agricultural or other applications models to investigate responses to a range of plausible trends, on which are superimposed decade-scale climate fluctuations whose likelihood of occurrence can be estimated.

 

Read the full post: New paper explores the wild card of decadal variability when simulating future climate scenarios