Question

Global warming has been linked to the growth of population of some insects and pests in cooler areas where they have not been previously seen. What global systems does this population growth affect? Identify a positive and a negative feedback resulting from it.

Answer 1

The losses will come from an increase in insect metabolism, and from faster insect population growth rates. The link with metabolism is straightforward. "When the temperature increases, the insects' metabolism increases so they have to eat more,"

The link with population growth, however, is more complex. Insects have an optimal temperature where their population grows best. If the temperature is too cold or too hot, the population will grow more slowly. That is why the losses will be greatest in temperate regions, but less severe in the tropics.

"Temperate regions are not at that optimal temperature, so if the temperature increases there, populations will grow faster," "But insects in the tropics are already close to their optimal temperature, so the populations will actually grow slower. It's just too hot for them."

According to the study, wheat, which is typically grown in cool climates, will suffer the most, as increased temperatures will lead to greater insect metabolism, as well as increased pest populations and survival rates over the winter. Maize, which is grown in some areas where population rates will increase and others where they will decline, will face a more uneven future.

In rice, which is mostly grown in warm tropical environments, crop losses will actually stabilize if average temperatures rise above 3°C, as population growth drops, counteracting the effect of increased metabolism in the pests. "Rice losses will taper off as the temperature rises above a certain point,"

Crop losses for critical food grains will increase substantially as the climate warms, as rising temperatures increase the metabolic rate and population growth of insect pests, according to new research.

"Climate change will have a negative impact on crops,"