‘In 60 years, climate change took seven years of agri-productivity growth’

Ariel Ortiz-Bobea

is an economist and teaches at

Cornell University

. Speaking to

Times Evoke

, he discusses his research findings on how

climate change

is impacting agricultural productivity — and the implications of this:


My research seeks to understand the historical and future impacts of climate change on the economy — and particularly on agriculture. Anthropogenic climate change has already impacted agriculture. In 2021, my colleagues and I conducted a global study examining the impacts of climate change on agricultural productivity. This encompassed crops, speciality crops, tree crops, livestock, etc. — about 99. 9% of global agricultural production was captured in this study which had country-level data of productivity since the 1960s. We found that when a country experienced warming conditions or raised temperatures, it tended to experience lower agricultural productivity — to produce the same outputs, you would need more inputs. The inputs you’d be investing currently would be less productive in warmer years.





We then took our study into a parallel world without anthropogenic climate change where weather conditions were not impacted by human activity leading to greenhouse gases accumulating in the atmosphere. Such a world would have been considerably cooler than the one we are in. Studying both these worlds since 1960, we found agricultural productivity would have grown faster in the world without anthropogenic climate change. Human caused climate change is slowing down the growth of agricultural productivity and the magnitude of this is not small — over the last 60 years, this has wiped out seven years of growth in agricultural productivity.

HOW DOES YOUR GARDEN GROW?: Climate impacts are significantly reducing the growth of agri-productivity, a cause for worry as the world's population rises. Picture: iStock




Also, across multiple empirical models, we found these historical impacts were larger in countries around the equator. Tropical regions tended to be hit much harder than temperate regions which also includes India’s agri-productivity growth. The implications for food security and employment in these countries are worrying. One of the implications of these findings is that we will need far more investments in research and development as well as generating alternative livelihoods to counterbalance this headwind.

STORM IN

A COFFEE CUP

: Climate change is already impacting coffee production, with higher temperatures, drier soils and unusual frost damaging crops and pushing up global prices. Picture: iStock

Importantly, much more rapid changes in agricultural productivity are projected. We found that agriculture is becoming even more sensitive to high temperatures over time — this means the slowdown effect could be magnified. Already, data shows that for the same change in temperature, the slowdown was a certain amount in the 1960s — but this became higher in the 1980s. This calls for much more investment in building resilience.

We are already seeing agricultural productivity stalling in sub-Saharan Africa, one of the regions with the least investment in technological development to boost farming productivity. Our findings have serious implications for global food production which could reduce — when supplies fall short, food prices go up. Farmers respond by trying to grow more through increasing inputs but this means more polluting fertilisers and more land being cleared of forests.



This is not a sustainable way to bolster agriculture. Instead of increasing inputs, we need to learn how to make the most of the inputs we’re putting in now. That knowledge can only come from investments in research. As this takes decades to be translated to technology, the urgency of investing in it has never been more pressing. The problem we face is also at a scale that requires deep systemic change. India should think about the sustainability of water used in growing crops — are current pricing systems encouraging more use of water than needed? This is just one issue that needs careful thought when we consider agri-productivity, climate change and the future of food.