Animals: How can Animals Deal with Climate Change?

17 minute read

Updated on Fri Feb 26 2021

Because of melting sea ice, nearly all polar bears will be gone by 2100. And it’s not just polar bears: many species are at risk from the changing climate.

Earthly hugging penguin

In fact, scientists now think the planet is facing a mass extinction, partly due to climate change. But what does this actually mean?

Animals, plants, fungi, and bacteria are all examples of living “organisms”. They all have things in common - like the ability to move, eat and grow. Many of them are also likely to be affected by climate change.

Organisms can be grouped into different species. When there are no more individuals of that species left alive we call that species extinct. The “lifespan” of a species varies, but scientists estimate that species exist for between 1 and 10 million years.

Extinction Record

Recent extinctions

How much faster is the estimated current rate of extinction, compared with normal extinction rates (calculated using fossils)?


While it is natural that species go extinct, the rate of extinction is increasing due to human activities and human-caused climate change.

Extinction rates of the past, present and future

Around 1 million plant and animal species are thought to be threatened with extinction, partly because global warming is happening so fast.

The battleground for survival is made harder by additional threats from humans, such as pollution and deforestation, which destroy the homes of many species.

Besides complete extinctions, it is clear that many population sizes are also decreasing globally. Between 1970-2014, the sizes of over 16,000 vertebrate populations from 4,000 species have declined by 60% on average.

Living Planet Index

How does climate change actually cause extinction?

There are a few key causes. For example:

  • Heatwaves, such as in Australia where 23,000 flying foxes died from overheating in 2018.
  • Rises in sea level reduce land availability. This means animals might have less access to food and living areas, which reduces their chance of survival.
  • Seawater floods make the land and water saltier. This is problematic for plants that aren’t adapted to salty environments as it causes water to be drawn out of their cells, dehydrating them.

The Ocean

The ocean plays an important role in keeping conditions on Earth constant by absorbing both heat and CO₂ from the atmosphere. While this buffering might be good for us on land, organisms that live in the ocean are taking the hit underwater. Let's look at an example:

Coral reefs are home to hundreds of thousands, if not millions, of species. This makes them some of the most biodiverse places on Earth.

Coral reefs are full of life

Coral reefs:

  • Provide homes for a quarter of all fish species.
  • Protect people from floods and storms by breaking waves.
  • Provide income to at least 94 countries by attracting tourism.

When stressed by temperature increases, corals turn white and starve. This is called coral bleaching.

Coral bleaching

We have already reached 1.0°C warming. Coral reefs are so sensitive that if temperatures reach 1.5°C above pre-industrial levels, it is predicted that 70 to 90% of them will be lost. If we reach 2°C, nearly all coral reefs will be lost.

Life in the ocean is also made worse by an issue known as ocean acidification: when the ocean absorbs the CO₂ we are releasing into the atmosphere, it becomes more acidic. This can interfere with chemical reactions that ocean species rely on to survive.

What can species do?

To avoid going extinct in the face of climate change, many species have only three options to stay alive.

What can species do in the face of climate change?

Be Flexible

Organisms can adapt their behaviour to better survive different conditions.

For example, flooding land with seawater makes it very salty, which can dehydrate plants. Plants that adapt to regulate their fluids will be better adapted to deal with more frequent flooding.

Species must adapt their behaviour to cope with floods

Migration

By 2050, what percentage of land-based ecosystems are predicted to have a changed climate?


One way wildlife can respond is by migrating (moving) to a more suitable habitat. Species are generally migrating towards the poles (by 17km per decade) or uphill (by 11m per decade) to reach cooler temperatures.

Migration to the poles

Evolve

Over longer timescales, changes may occur in the organism’s DNA. When new and useful genes appear in an individual, they can spread through a population over many generations.

Which of the following could be genetic adaptations to climate change?


Are organisms adapting fast enough?

Unfortunately, it is unlikely that all species can migrate fast enough to keep up with predicted temperature changes.

On average, how far do species on land need to move each year to keep up with climate change?


This is about 10x faster than species needed to move during the climate change at the end of the last ice age. Plus, species might run out of places to go, if they meet barriers or reach the top of a mountain.

Some species have nowhere left to go when they’re already at the top of a mountain, stuck on an island, or at the poles.
Geographical barriers, like large bodies of water, or human uses of land (like farmland and roads) split up suitable migration routes.
Things like body shape, energy levels and method of transport can affect travel speed!

Conclusion

Climate change is just one of many significant threats to our planet’s wildlife. The fast rate of global warming might mean that species can’t adapt or migrate fast enough to survive. We must slow down the pace of warming if we want to protect ecosystems and the services they provide to humans.

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