Can species and ecosystems adapt?
Climate strongly affects plants and animals. Every species on Earth evolved to function best within certain temperature and moisture limits. As the climate warms, plants and animals are trying to adapt.
Plants are flowering earlier, birds migrating and laying eggs earlier. Thousands of examples of change like these from around the globe send a hugely strong message that species and ecosystems are already responding to the 1° Celsius of warming so far.
But today plants and animals face two important obstacles as they try to adapt further:
The climate is changing too fast
Earth's long climate record shows that past rapid warming events almost always caused mass extinctions of plants and animals — because life had no time to adapt. Yet today warming is set to take place 10 times faster than any change recorded in the past 65 million years.
Rapid warming is already harming fragile ecosystems, including coral reefs. It's also causing extinctions — complete and permanent loss of unique forms of life.
Habitat loss and damage hinder adaptation
One important way plants and animals can adapt is to shift across landscapes. In this way, they may track suitable conditions as the climate warms. Today many plants and animals are trying to do this — moving toward the poles, up the flanks of mountains, or into deeper ocean waters.
Yet unlike in the past, cities, freeways and farms now block their progress. Pollution and other types of stress caused by humans further weaken their ability to adapt.
If they cannot shift, and local climates warm, dry out, or change in other ways to create conditions they can no longer tolerate, plant and animal populations will die out.
The climate extinction threat
Climate change is already causing extinctions, scientists say. Costa Rica's golden toad, along with dozens of harlequin frog species in the American tropics, were the first recorded victims.
In future, one in every six species could face extinction with a global temperature rise of 4.3° Celsius. Less severe warming of 2° Celsius would still bring on an estimated extinction rate of 5.2 percent. That's almost double today's 2.8 percent extinction rate — which scientists warn is already driving a mass extinction crisis.
Some climates will completely disappear
As the globe warms, some climates will be lost altogether. Climates most at risk are at the poles, the pole-ward ends of some continents, and the tops of tropical mountains. Species that depend on these vanishing climates — like emperor penguins, polar bears, and many tropical mountain forest birds — will simply have nowhere to go.
Disappearing climates also roughly match biodiversity hotspots of tropical mountain regions. In these hotspots, large numbers of species are packed into relatively small areas already facing many other human threats. So climate change adds further stress for plants and animals in these important but threatened ecosystems.
Coral reefs already at risk
To preserve more than 10 percent of the world's corals, global temperature increase must stay under 1.5° Celsius. Limiting climate warming to 2° Celsius is unlikely to save most coral reefs.
When coral is lost, the sea creatures it hosts lose their habitat, and food webs that connect wildly diverse ocean life of these reefs are disrupted.
Severe ocean threat: the carbon dioxide - acid link
Each year oceans absorb about one third of the extra carbon dioxide building up in the atmosphere from burning coal, oil and gas. This carbon dioxide dissolves in seawater as a weak acid.
The acidity of ocean surface waters has already increased by about 30 percent on average (a pH shift from 8.2 to 8.1)
Oceans are acidifying 10 to 100 times faster than any time in the past 50 million years.
As the ocean's acid content increases, sea creatures — from tiny plankton and sea snails to corals in vast reefs — are less able to build up shells and other hard body parts they need to survive. Scientists fear these acidity increases could cause even more harm to ocean life than warming waters.
What is Greenpeace doing?
To avoid a climate catastrophe Greenpeace is driving an urgent shift away from the polluting energy sources that are destroying the lands and oceans we love. Help us make the urgent leap to a future built on 100 percent clean, safe energy from the sun, wind, and other renewable sources — our best chance for the planet.
And because healthy oceans can fight many impacts of climate change, Greenpeace is calling for a global network of ocean sanctuaries (marine reserves).
As part of this network, Greenpeace is asking world leaders to create a global sanctuary in the uninhabited area around the North Pole, and to ban oil drilling and destructive fishing in Arctic waters.
What can you do?