Climate change is a contributory factor to the food price crisis, and its impact on agriculture and food security in developing countries is expected to get more serious.
by Brett Harris
from People and Planet
Climate change is already affecting food security and it is expected to have even greater impacts in coming years.
There are at least four channels by which climate change affects food security:
- Temperature increase. Higher temperatures lead to heat stress for plants, increasing sterility and lowering overall productivity. Higher temperatures also increase evaporation from plants and soils, increasing water requirements while lowering water availability.
- Changing patterns. In many places, growing seasons are changing, ecological niches are shifting, and rainfall is becoming more unpredictable and unreliable both in its timing and its volume. This is leading to greater uncertainty and heightened risks for farmers, and potentially eroding the value of traditional agricultural knowledge such as when to plant particular crops.
- Rising sea levels. Rising seas contaminate coastal freshwater aquifers with salt water. Several small island states are already having serious problems with water quality, which is affecting agricultural productivity. Higher seas also make communities more vulnerable to storm surges which can be 5-6 metres high. The storm surge from cyclone Nargis travelled 35 kilometres inland, killing 140,000 people and flooding around 14,400 km, an area one third the size of Switzerland.
- Water. The interactions between climate change, water scarcity and declines in agricultural productivity could lead to regional tensions and even open conflict between states already struggling with inadequate water supplies due to rising populations and over-pumping of groundwater. “
Heightened risks for farmers
In its 2007 report, the IPCC projected a sea-level rise of less than one metre this century, emphasising that this does not take into account the dynamic processes in ice sheets related to ice flow. Once ice sheet dynamics are factored in, two metres is entirely possible this century, and we also could cross a threshold which guarantees several metres of sea-level rise next century. Even a one-metre sea-level rise would displace more than 145 million people and would contaminate drinking water and agricultural land for tens of millions more.
The geo-political implications of water projections for Asia in particular are extremely serious. Increased glacier melt from the Himalayas and Tibetan Plateau in the next 20-30 years is likely to increase flooding, and by the late 2030s, glacier-fed river flows are expected to decrease dramatically as the glaciers shrink.
The Middle East, Southern Africa and the Mediterranean basin also are expected to be afflicted by severe water shortages. Widespread water shortages almost certainly would lead to widespread food shortages, which would trigger large movements of people and, potentially, major armed conflicts with staggering humanitarian and economic costs.
Preparing for unavoidable change
Drastic reductions in greenhouse gas emissions are an essential component of a global food security strategy to prevent climate change from becoming catastrophic. Our current trajectory is sending us towards warming of around 5-6ºC above pre-industrial levels, which — if it continues for many more decades — would lead to famines beyond imagining and would almost certainly guarantee sea-level rises of around 12 metres.
The IPCC concluded that to have an even chance of keeping warming to around 2ºC — not a safe level but possibly tolerable — the rich countries need to reduce their emissions by 25-40 per cent below 1990 levels by 2020 and 80-95% below 1990 levels by 2050; developing countries also need to reduce their emissions below their “business as usual” rate.
Developing countries urgently need more assistance to help them prepare for the impacts of climate change that are unavoidable. Such assistance should include transfer of the industrialised countries’ best energy efficiency and renewable energy technology and assistance with disaster preparedness, agricultural productivity improvements, water management, conflict prevention, reforestation, preventing deforestation and critical infrastructure.
It would be a mistake to treat the most recent food price crisis as an isolated short-term phenomenon. Much larger and longer-term forces are at work that demand urgent action. Sustained and systematic attention is crucial if we are to avoid a humanitarian catastrophe — a phrase that I do not use lightly.
Dr Brett Parris is Chief Economist for World Vision Australia. This is an edited version of an article which first appeared in Global Future, Edition 3, 2008, a publication of World Vision.