The negative effects of global warming on food supply and security

Food Climate-related threats to global food production include risks to grain, vegetable, and fruit crops, livestock, and fisheries. See how global warming threatens food production in Vietnam —and find other hot spots with food impacts on the Climate Hot Map. The productivity of crops and livestock, including milk yields, may decline because of high temperatures and drought-related stress. Regions of the world that now depend on rain-fed agriculture may require irrigation, bringing higher costs and conflict over access to water.

The negative effects of global warming on food supply and security

The differences among countries in simulated crop yield responses to climate change without the direct effects of CO2 are primarily related to differences in current growing conditions. Higher temperatures tend to shorten the growing period at all locations tested.

At low latitudes, however, crops are currently grown at higher temperatures, produce lower yields, and are nearer the limits of temperature tolerances for heat and water stress.

Warming at low latitudes thus results in accelerated growing periods for crops, more severe heat and water stress, and greater yield decreases than at higher latitudes.

In many mid- and high-latitude areas where current temperature regimes are cooler, increased temperatures, while still shortening grain-filling periods, thus exerting a negative influence on yields, do not significantly increase stress levels.

At some sites near the high-latitude boundaries of current agricultural production, increased temperatures can benefit crops otherwise limited by cold temperatures and short growing seasons, although the extent of soil suitable for expanded agricultural production in these regions was not studied explicitly.

Potential for expansion of cultivated land is embedded in the BLS world food trade model and is reflected in shifts in production calculated by that model. The UKMO climate change scenario, which has the greatest warming 5.

Climate Change Impacts

For example, at present, many Mexican producers can only afford to use small doses of nitrogen fertilizer at planting; if more fertilizer becomes available to more farmers some of the yield reductions under the climate change scenarios might be offset. However, given the current economic and environmental constraints in countries such as Mexico, a future with unlimited water and nutrients is unlikely Liverman et al.

In contrast, switching from spring to winter wheat at the modelling sites in the former USSR produces a favourable response Menzhulin et al. Adaptation Level 1, simulating minor changes to existing agricultural systems, compensated for the climate change scenarios incompletely, particularly in the developing countries.

Adaptation Level 2, implying major changes to current agricultural systems, compensated almost fully for the negative climate change impacts in the GISS and the GFDL scenarios. With the high level of global warming as projected by the UKMO climate change scenario, neither Level 1 nor Level 2 adaptation fully overcame the negative climate change effects on crop yields in most countries, even when the direct CO2 effects were taken into account.

Modelling the world food system The world food system consists of many actors, some powerful and others dependent. Producers and consumers interact through national and international markets. National governments shape the system by imposing regulations and by investments in agricultural research, improvements in infrastructure, and education.

Although the system does not guarantee stability nor equity, food and fibre have been produced over time in increasingly efficient ways. These efficiencies have generated long-term real declines in prices of major food staples. The individual models are linked together by means of a world market module.

A detailed description of the entire system is provided in Fischer et al. Earlier results obtained with the system are discussed in Parikh et al. The BLS is a general equilibrium model system.

The negative effects of global warming on food supply and security

This necessitates that all economic activities are represented in the model. Financial flows as well as commodity flows within a country and at the international level are consistent in the sense that they balance.Climate change ‘already affecting food supply ‘ – UN that climate change could threaten global food security that caught the warming effects have a negative Researchers from the UK, China, Mexico and the US studied the effect of a warmer planet on barley yields.

Chapter 7, "Food security and food production systems," details the current effects of climate change, the expected decline in crop production by as a result of climate change, and what farmers can do to mitigate some of the negative impacts.

As stated by the chapter authors: "The questions for this chapter are how far climate and its. A new study attempts to estimate the effects of climate change on global agriculture--and outline ways to mitigate its most dire consequences and Food Security: which will have negative.

The negative effects of global warming on humans may be most significant on food supplies and security. Wheat, rice, and maize production in tropical and temperate regions are anticipated to vary widely in yields, with severe yield impacts significantly increasing after , depending on global temperatures.

The negative effects of global warming on humans may be most significant on food supplies and security. Wheat, rice, and maize production in tropical and temperate regions are anticipated to vary widely in yields, with severe yield impacts significantly increasing after , depending on global temperatures.

With the high level of global warming as projected by the UKMO climate change scenario, neither Level 1 nor Level 2 adaptation fully overcame the negative climate change effects on crop yields in most countries, even when the direct CO 2 effects were taken into account.

Climate Impacts on Agriculture and Food Supply | Climate Change Impacts | US EPA