Up to half of plant and animal species in the world’s most naturally rich areas, such as the Amazon and the Galapagos, could face local extinction by the turn of the century due to climate change if carbon emissions continue to rise unchecked. Even if the Paris Climate Agreement 2°C target is met, these places could lose 25% of their species according to a landmark new study by the University of East Anglia, the James Cook University, and WWF.
Published today in the journal Climatic Change and just ahead of Earth Hour, the world’s largest environmental event, researchers examined the impact of climate change on nearly 80,000 plant and animal species in 35 of the world’s most diverse and naturally wildlife-rich areas. It explores a number of different climate change futures – from a no-emissions-cuts case in which global mean temperatures rise by 4.5°C, to a 2°C rise, the upper limit for temperature in the Paris Agreement. Each area was chosen for its uniqueness and the variety of plants and animals found there.
What climate change means for species
The report finds that the Miombo Woodlands, home to African wild dogs, south-west Australia and the Amazon-Guianas are projected to be some the most affected areas. If there was a 4.5°C global mean temperature rise, the climates in these areas are projected to become unsuitable for many the plants and animals that currently live there meaning:
- Up to 90% of amphibians, 86% of birds and 80% of mammals could potentially become locally extinct in the Miombo Woodlands, Southern Africa
- The Amazon could lose 69% of its plant species
- In south-west Australia 89% of amphibians could become locally extinct
- 60% of all species are at risk of localised extinction in Madagascar
- The Fynbos in the Western Cape Region of South Africa, which is experiencing a drought that has led to water shortages in Cape Town, could face localized extinctions of a third of its species, many of which are unique to that region.
As well as this, increased average temperatures and more erratic rainfall could become be the “new normal” according to the report – with significantly less rainfall in the Mediterranean, Madagascar and the Cerrado-Pantanal in Argentina. Potential effects include:
- Pressure on the water supplies of African elephants – who need to drink 150-300 litres of water a day
- 96% of the breeding grounds of Sundarbans tigers could become submerged by sea-level rise
- Comparatively fewer male marine turtles due to temperature-induced sex assignment of eggs.
Can we save our Wildlife
If species can move freely to new locations then the risk of local extinction decreases from around 25% to 20% with a 2°C global mean temperature rise. If species cannot they may not be able to survive. Most plants, amphibians and reptiles, such as orchids, frogs and lizards cannot move quickly enough keep up with these climatic changes.
Lead researcher Prof Rachel Warren from the Tyndall Centre for Climate Change Research at UEA said “Our research quantifies the benefits of limiting global warming to 2°C for species in 35 of the world’s most wildlife-rich areas. We studied 80,000 species of plants, mammals, birds, reptiles and amphibians and found that 50% of species could be lost from these areas without climate policy. However, if global warming is limited to 2°C above pre-industrial levels, this could be reduced to 25%. Limiting warming to within 1.5°C was not explored, but would be expected to protect even more wildlife.”
Overall the research shows that the best way to protect against species loss is to keep global temperature rise as low as possible. The Paris Agreement pledges to reduce the expected level of global warming from 4.5°C to around 3°C, which reduces the impacts, but we see even greater improvements at 2°C; and it is likely that limiting temperature rise to 1.5°C would protect more wildlife.
This is why on 24 March millions of people across the world will come together for Earth Hour, to show their commitment to reducing global emissions and protecting people and wildlife from the impacts of climate change. The event also sends a clear message to business and government that there is a global will to change this trajectory.
What individual species will experience:
- Orang-Utans have a solitary life-style which allows them to move to cope with reduced food availability due to changing climates. However, females are strictly bound to their territories, which will prevent them from moving, and can put them at risk as there is a general reduction in available forest habitat due to deforestation, climate change and other human pressures
- Snow leopards already live under extreme conditions with very little margin for changes which makes them particularly sensitive to changes in climate. Their habitat will shrink by 20% due to climate change and will put them into greater direct competition over food and territory with the common leopard, which will likely lead to a further decline in numbers.
- Tigers live in highly fragmented landscapes and will be greatly impacted by further climate-induced habitat loss. For example, projected sea level rise will submerge 96% of breeding habitat for the Sundarbans tigers, and Amur tigers are unlikely to persist to the next century if the size and quality of their habitat is reduced.
- Polar bears are among the most sensitive to climate change because they depend on sea ice to live and eat. Younger polar bears that are not as practiced hunters are particularly affected by food shortages due to shrinking sea ice. Polar bears in some areas are already in decline – for example, the population in Hudson Bay has been already reduced by 22% – and are predicted to sharply decline by the end of the 21st century due to climate change.
- Marine Turtles are highly sensitive to climate warming. While adults have been known to move to avoid too warm waters, a changing climate will impact greatly on their offspring. Tortoises and turtles are among the species with temperature-dependent sex determination. Warmer temperatures will produce more females resulting in a dangerous sex bias. Also increased flooding will increase egg mortality and warmer sand will also produce smaller and weaker hatchlings.