How does climate change cause extinction?

Question 1

What are the other potential proximate causes of extinction, even when anthropogenic climate change is the ultimate cause?

Answer 1

Negative impacts of heat-avoidance behaviour, the climate-related loss of host and pollinator species and positive impacts of climate change on pathogens and competitors.

Question 2

Proximate factors causing extinction from
climate change
(a) Abiotic factors
(i) Temperature ( physiological tolerances)

Answer 2

Temperatures that exceed the physiological
tolerance of the species
Air temperatures may both decrease activity time and increase energy maintenance costs, leading organisms to die from starvation rather than from overheating

Question 3

Proximate factors causing extinction from
climate change
(a) Abiotic factors
(ii) Precipitation ( physiological tolerances)

Answer 3

For example, decreasing precipitation may lead
directly to water stress, death and local extinction for terrestrial species , and loss of habitat for freshwater species or life stages. There may also be synergistic effects between heat and drought stress (e.g. in trees).

Question 4

Proximate factors causing extinction from
climate change
(b) Biotic factors

Answer 4

(i) Negative impacts on beneficial species
Climate change may cause local extinction of a given species by causing declines in a species upon which it depends.

(ii) Positive impacts on harmful species
Alternately, climate change may cause extinction through positive effects on species that have negative interactions with a focal species, including competitors, and pathogens.

(iii) Temporal mismatch between interacting species
Climate change may also create incongruence between the activity times of interacting species.