Climate change and roots and tubers Andy Jarvis, Julian Ramirez, Emmanuel Zapata

Contents About climate change and predictive models Expected changes for potato and cassava growing regions Implications on suitability Challenges ahead

About climate change and predictive models

Expected changes for potato and cassava growing regions

Implications on suitability

Challenges ahead

How can we be sure that it is changing?

Arctic Ice is Melting

In order to prepare, we need to know what to prepare for…. … .but how?

… .but how?

Global Climate Models (GCMs) 21 global climate models in the world, based on atmospheric sciences, chemistry, biology, and a touch of astrology Run from the past to present to calibrate, then into the future Run using different emissions scenarios

21 global climate models in the world, based on atmospheric sciences, chemistry, biology, and a touch of astrology

Run from the past to present to calibrate, then into the future

Run using different emissions scenarios

So, what do they say?

Changes in rainfall…

CIAT’s Data 18 GCM models to 2050, 9 to 2020 Different scenarios, A1b, B1, commit Downscaled using empirical methods http://gisweb.ciat.cgiar.org/GCMPage/

18 GCM models to 2050, 9 to 2020

Different scenarios, A1b, B1, commit

Downscaled using empirical methods

Changes in Cassava production areas in Latin America

The Impacts on Crop Suitability

The Model: EcoCrop So, how does it work? It evaluates on monthly basis if there are adequate climatic conditions within a growing season for temperature and precipitation… … and calculates the climatic suitability of the resulting interaction between rainfall and temperature…

So, how does it work?

Agricultural systems analysis 50 target crops selected based on area harvested in FAOSTAT

50 target crops selected based on area harvested in FAOSTAT

Average change in suitability for all crops in 2050s

Winners and losers Number of crops with more than 5% loss Number of crops with more than 5% gain

And potato???

Current Suitability Suitability 2020

Current Suitability Suitability 2050

Change in suitability 2020 Change in suitability 2050

Impacts on production of cassava

Worldwide cassava production climatic constraints Grey areas are the crop’s main niche. Blue areas constrained by precipitation Yellow-orange constrained by temperature

Grey areas are the crop’s main niche.

Impact of climate change on cassava suitable environments Global cassava suitability will increase 5.1% on average by 2050… but many areas of Latin America suffer negative impacts

What are the expected global benefits? Increase of 5-10% in potential land area for cassava when implementing either drought or flood tolerance 21.9 million hectares (16.9% of global cassava fields) under cultivation would benefit 63.3 million hectares of new land would become suitable for cassava

…… .and for Latin America? Drought or flooding tolerance 30% of current cassava fields would benefit from enhanced drought or flooding tolerance 1.6m Ha still suffering climatic constraint 2.23m Ha of current production 2.1m Ha of new land would become suitable for cassava

…… .and for Latin America? Heat or cold tolerance 27% of current cassava fields would benefit from enhanced cold or heat tolerance 2.23m Ha of current production 2.2m Ha of new land would become suitable for cassava

Evaluating Technology Options: Crop Improvement for Cassava Grey areas would get no benefit from drought or flood tolerance. Blue areas benefit from drought tolerance improvement Purple areas benefit from flood tolerance improvement

Pest and Disease Impacts

Impacts on green mite to 2020

Impacts on whitefly to 2020

Challenges ahead Further analysis: improvement of the parameters, greater uncertainty in GCMs Inclusion of post-harvest impacts – drying for example Further work in pest and disease impacts … .but too late to wait for 100% certainty Crop improvement and targeted varietal selection can support adaptation

Further analysis: improvement of the parameters, greater uncertainty in GCMs

Inclusion of post-harvest impacts – drying for example

Further work in pest and disease impacts

… .but too late to wait for 100% certainty

Crop improvement and targeted varietal selection can support adaptation

GRACIAS!!!! [email_address]