Insects will struggle to keep pace with global temperature rise – which could be bad news for humans
Juveniles were able to modify their upper thermal limit by 11 per cent on average, compared to 7 per cent for adults.But given that their capacity to acclimate is still relatively weak and may fall as an insect leaves this life stage, the impact is likely to be limited for adjusting to future climate change.What does this mean for the future
Animals can only endure temperatures within a given range. The upper and lower temperatures of this range are called critical thermal limits. As these limits are exceeded, an animal must either adjust or migrate to a cooler climate.
However, temperatures are rising across the world at a rapid pace. The record-breaking heatwaves experienced across Europe this summer are indicative of this. Heatwaves such as these can cause temperatures to regularly surpass critical thermal limits, endangering many species.
In a new study, my colleagues and I assessed how well 102 species of insect can adjust their critical thermal limits to survive temperature extremes. We found that insects have a weak capacity to do so, making them particularly vulnerable to climate change.
The impact of climate change on insects could have profound consequences for human life. Many insect species serve important ecological functions while the movement of others can disrupt the balance of ecosystems.
How do animals adjust to temperature extremes? An animal can extend its critical thermal limits through either acclimation or adaptation.Acclimation occurs within an animal's lifetime (often within hours). It's the process by which previous exposure helps give an animal or insect protection against later environmental stress. Humans acclimate to intense UV exposure through gradual tanning which later protects skin against harmful UV rays.
One way insects acclimate is by producing heat shock proteins in response to heat exposure. This prevents cells from dying under temperature extremes.
Some insects can also use color to acclimate. Ladybirds that develop in warm environments emerge from the pupal stage with fewer spots than insects that develop in the cold. As darker spots absorb heat, having fewer spots keeps the insect cooler.
Adaptation occurs when useful genes are passed through generations via evolution. There are multiple examples of animals evolving in response to climate change. Read More…
