Impact of Global Warming and Climate Change On Agriculture

As our climate continues to heat up and the impacts of that warming grow more frequently and severely, the farming communities around the world will be increasingly challenged. And Indian farmers won’t be spared at any cost, of the damage that climate change is already beginning to beget.

What is Global Warming?

Global warming is the long-term heating of Earth’s climate system observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere.

(Source: NASA – Global Warming Vs Climate Change)

Global warming affects agriculture in a number of ways, through changes in average temperatures, rainfall, and climate extremities (e.g., heat waves); changes in pests and diseases; changes in atmospheric carbon dioxide  concentrations; changes in the nutritional quality of some foods and changes in sea level.

Agriculture is a larger share of developing economies than of industrial economies. It has been widely accepted that developing countries in general will be more affected from the global warming impacts on agriculture than developed countries. This is because of the less adaptability of the developing countries to the changing situation than the developed ones. Most are in warmer parts of the globe, where temperatures are already close to or beyond thresholds at which further warming will reduce rather than increase agricultural output.

In the long run, the climatic change could affect agriculture in several ways:            

  • By inducing more extreme weather such as floods, drought and storms.
  • By changing overall growing conditions (general rainfall distribution, temperature regime )
  • Change in productivity as a whole in terms of quantity and quality of crops.
  • Change in agricultural practices, through changes in irrigation pattern and agricultural inputs such as herbicidesinsecticides and fertilizers.
  • Environmental effects related to soil drainage (leading to nitrogen leaching) and soil erosion.
  •  Forced development of more competitive organisms, such as flood resistant or salt resistant varieties of cereal crops like rice.

Global Climate Change Trends

There have been changes in some types of extreme weather events over the last several decades. Heat waves have become more frequent and intense, especially in the West. Cold waves have become less frequent and intense across the nation. There have been regional trends in floods and droughts.

(Source: Global Climate Trends | National Climate Assessment)

Pest Insects and Climate Change

Global warming could lead to an increase in insect pest populations, impairing  yields of staple crops like wheat and soybeans. As warmer temperatures are conducive for pests  it increases the metabolic rate and number of breeding cycles of insect causing a population boom.

Studies conducted at the University of Illinois  found that the soybeans with elevated CO2 levels grew much faster and had higher yields, but attracted Japanese beetles at a significantly higher rate . The beetles in the field with increased CO2 also laid more eggs on the soybean plants and had longer lifespans, indicating the possibility of a rapidly expanding population.

Pest Insects and Climate Change

The biggest consequence of climate change on the dispersal of pathogens is that there could be shift in geographical distribution of hosts and pathogens which would result in more crop losses. Global warming would cause an increase in rainfall in some areas, which would lead to an increase of atmospheric humidity and the duration of the wet seasons. Along with higher temperatures, these could favour the proliferation of fungal diseases.

Changing Precipitation Patterns

Rainfall patterns have already begun shifting across the continents, and such changes are expected to intensify over the coming years. In that case we are likely to witness more intense stretch of heavy rain and longer dry spells , even within the same regions.

Changing Temperature Patterns

Rising average temperatures, severe heat throughout the year, fewer cool days during the winter, and more frequent cold-season thaws will likely affect farmers in all regions of the world.

Reducing Damage By Making Farms More Resilient

Progressive farmers and scientists are finding new climate-resilient ways to produce food:

  • Crop diversification and breeding more enduring  crop varieties.
  • Using improved agro forestry species and native perennial crops to create a diverse agro ecosystem.
  • Collection and conserving rain water and use of improved irrigation practices.
  • Increasing forest cover, planting cover crops and deep-rooted perennials—that increases water holding capacity of soil to soak up heavy rainfall and retain water for dry periods.
  • Use of latest water harvesting techniques such as contour trenching.

It’s crucial that we provide farming communities with the support they need to survive the climate change and global warming crisis and become more resilient. This includes better crop insurance programs, access of health care services to farmers and responsive disaster relief and management programs.


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