A3.7.2.2 Continued…
Oceans & Seas:
Like forests, oceans are vital ‘carbon sinks’ – they absorb huge amounts of CO2, preventing it from reaching the upper atmosphere. But increased water temperatures and higher than normal CO2 concentrations, causing ocean acidification, are already having an impact.
Coral reefs and shellfish are particularly at risk – sensitive coral (and algae living on it) is starved of oxygen, causing dramatic bleaching and eventual death of the coral. The increasing number of tropical storms doesn’t help. And as seawater becomes more acidic (less alkaline), it’s harder for many alkaline-loving sea creatures to grow proper hard calcium shells. In the ‘Coral Triangle’ – a vast area of ocean around Malaysia and the Philippines, also called the “Nursery of the seas” because of its ecological importance – more than 85% of the precious coral is endangered.
If global warming stays on its upward path, by 2050 just 5% of Australia’s Great Barrier Reef – the world’s largest coral reef – will remain.
It’s not only a tragedy for wildlife: around half a billion people – a 12th of the entire population of the world – rely on fish from coral reefs as their main source of protein. If the coral reefs are destroyed, so is this vital larder for the planet.
On some beaches in northern Australia and in Latin America, there are already signs that more female marine turtles are being born than males – warmer nests tend to produce female hatchlings in this species, so it’s another indication of rising temperatures. Whales may well suffer from climate change too – on top of all the other manmade hazards they face – because their usual food sources, such as tiny shrimp-like krill and squid, may die off or migrate away from warming seas.
Warming seas around Britain could diminish shellfish stocks here, as well as causing damage to rare species like pink sea ferns, already threatened by seabed trawling methods. It’s also very possible that cod – an iconic cold-water fish that’s at its southern limit in our seas, and already seriously depleted from overfishing – may move north and be lost from UK waters altogether.
Polar Regions:
The Earth’s north and south extremities are crucial for regulating our planet’s climate – and are particularly vulnerable to the impacts of global warming.
The effects of climate change are already being felt by local wildlife and habitats in polar regions. For example, polar bears and Emperor penguins, at the north and south pole respectively, are already declining in number as sea ice disappears for many months of the year.
They effectively have less space to share, and less food to go around, which affects breeding patterns and numbers. And this decline will accelerate the longer global warming is allowed to continue. But the effect of climate change on the poles also has very serious consequences for people and wildlife all across the world.
Climate change in the Arctic
Climate change is having a greater and faster impact on the Arctic than previously thought. Air temperatures in the region have on average increased by about 5°C over the last 100 years.
The results of the 2009 Catlin Arctic Survey back up the new consensus view that there will be almost no summer sea ice cover left in the Arctic by 2020. This has severe implications – not just loss of polar bear and seal habitat, and knock-on effects on local people, but dramatic changes to the entire northern hemisphere. An open, ice-free Arctic Ocean will attract more shipping, commercial exploitation and pollution. The Arctic holds the world’s largest remaining untapped gas reserves and some of its largest undeveloped oil reserves. The lack of a permanent ice shield will also result in even faster warming (and acidification) of the seas, and acceleration of global climate change.