Ch27 Climate Change

What historical time period is credited as the start of humans exponentially increasing global warming/climate change?

The Industrial Revolution (way more emissions and the greenhouse gas effect)

Has global warming been equal across Earth’s surface?

No, polar regions have warmed more than anywhere else, especially the Artic

Has climate change been equal across seasons?

No, winter months have showed more warming than other months, diurnal temperature ranges have decreased because the minimums are getting warmer

Has the global ocean temperature increased?

Yes, it has increased down to a depth of at least 3000 feet, warmer waters cause seawater to expand contributing to rising sea levels

Physiological stress as a result of global warming: Endotherms

they maintain a constant temperature but as the climate is shifting to being warmed the body sizes are getting smaller (Bergmann’s rule) to reduce overheating

Physiological stress as a result of global warming: Ectotherms

they rely on external sources of heat, as the temperature rises their metabolic activity increases exponentially, can overheat and kill them if they don’t migrate which means they can also lose food sources

Phenological mismatch

when the timing of life cycle events in interacting species is desynchronized.

Phenological Mismatch: Pollinators

pollinators are emerging earlier in spring than the plants they pollinate, the pollinators don’t get enough nectar and the plants don’t get pollinated

Phenological Mismatch: Birds

birds need to be synchronized with hatching eggs and food availability, but seasonal shifts are causing some to lay their eggs too early. The hatchlings then starve since there isn’t enough food to sustain all of them

Phenological Mismatch: Reptiles

Many reptiles, like sea turtles, have sex ratios controlled by nest temperatures. Since the climate is warming so too are the nests, now about 90% of hatchlings are females

Poleward shifts

to escape the rising temperatures, species are moving in the direction toward colder environments (the poles). They will run out of places to go, food sources may not move with them, they can become invasive toward the species already inhabiting that space, or they may not be able to move at all and die out.

Poleward shifts: Red foxes

red foxes are moving towards the Arctic, creating competition between them and the smaller arctic foxes

Top 5 Threats to Biodiversity:

H- habitat loss

I- invasive species

C- climate change

O- overexploitation

P- pollution

Habitat Loss

loss of habitat, animals no longer have a suitable place to live and can die out or invade other habitats. Deforesting is the biggest example

Habitat degradation

reduction in habitat quality (pollution in the form of chemicals, light, noise, and trash)

habitat fragmentation

a habitat is fragmented into smaller isolated patches (one big pond’s water level decreasing, resulting in smaller pond formations separated by the pond’s floor being elevated in certain areas)

Invasive species

exotic species establishing a large population in a new environment that negatively impacts native species and ecosystems

climate change

temperature and precipitation changes causing more droughts, deep freezes, flooding, heat waves, fires, and other natural disasters

overexploitation

unsustainable removal of organisms from their environment (like overfishing, poaching, or deforestation)

pollution

chemicals are released into the environment and impact both biotic and abiotic factors, trash (especially plastic) is being eaten by or entangling animals which kills them, light and sound pollution drive organisms away from habitats

What can we do about climate change?

• protect wildlands

• restore degraded ecosystems

• fund conservation agencies

• support scientific research

• increase public education and citizen science

• mitigate the effects of climate change