🐞 Impact of Global Warming on Insect Pests

This lesson explains global warming, the greenhouse effect, and how climate shifts influence pest dynamics, cropping systems, and agricultural risk management.

Lecture 26: IMPACT OF GLOBAL WARMING ON PESTS

What is global warming?

SUN Earth reflects some solar energy as infrared radiation

Green house gases

Infra red radiation from earth reflected back to earth by green house gases. This increases the Solar radiation temperature of earth and lower falls on earth atmosphere. This is called surface. Earth global warming or greenhouse absorbs and effect gets heated up EARTH

• Warmth from sun heats the surface of the earth

• Earth absorbs most of the energy but reflects back some energy in the form of infra red radiation

• Greenhouse gases (e.g. CO2, Methane, CFC (Chloro Fluoro Carbon), Nitrous oxide) present in atmosphere trans the infrared radiation and reflects back to earth

• This reflected energy falls on earth and also lower atmosphere and keeps it warmer (Heats the earth’s surface)

This is called global warming or green house effect.

Effect of global warming on world and agriculture

• Increase in overall temperature on earth (e.g.) Earth’s surface temperature has increased 1.4 [o] F in lst one century (Forecast: 5 [o] F rise in next century)

• Change in climate tremendously

• Melting of ice in Polar region

• Increase in seas level and submerging of coastal areas

• Flooding and intense down pours

• Drought in warmer regions

Impact of global warming on pest status

1. Due to change in climate, temperature and water availability, the farmers may

change the type of crops grown. 2. Due to increase in temperature, there can be outbreak of certain insect pests and

diseases.

3. In forest areas there will be a shift in tree species and also pest species.
4. In agriculture lands since cropping pattern is changed new crops to suit the

climate is introduced and new pests are also introduced. 5. When water availability is less, crops will be raised as rainfed. It will be difficult

to take up control measures without water.

Sources of green house gases

Developed countries : Emission from Automobiles and factories contain CFCs Developing countries : Deforestation causes rise in CO2 level Methane gas

from paddy fields and livestock Nitrous oxide from ‘N’ based fertilizer

Summary Cheat Sheet

• Global warming can shift pest distribution, increase survival, and alter the number of generations completed each year.

• Climate-driven changes in temperature and moisture influence insect development, migration, and outbreak risk.

• Understanding climate impact on pests is important for long-term IPM planning and future crop protection.

• Review core concepts, definitions, and field-level application points from this lesson.

• Prioritize economic threshold-based decisions and integrated management logic where relevant.