2016 has proved to be the hottest year on record for the third year in a row and now more than 1 in 6 species is at risk of extinction due to climate change. Earth Hour is a global movement that brings people together across the continents to call for greater action.
Last year a record number of 178 countries took part – a number that rises every year. From the Sydney Opera House and the Eiffel Tower to Buckingham Palace and Edinburgh Castle, cities, towns and communities like yours across the world switch out their lights and come together for an hour, to join a global show of support for action on climate.
So for just ONE HOUR at 8.30pm on Saturday March 25th (wherever you are) we are simply asking that you turn off your lights and power down as many things as you can.
And that’s all there is to it!!
Climate change poses a fundamental threat to everything we love. Melting glaciers, rising sea levels, and new and more frequent weather extremes will leave no continent untouched. Impacts are already being felt by many communities and ecosystems worldwide. Water supplies are shrinking, crop yields are dropping, forests are burning, and our oceans are becoming more acidic. This has huge implications for our livelihoods and human security.
The task and hand is managing the unavoidable impacts and, at the same time, mitigating the impact of future climate impacts.
To have a chance of preventing dangerous global warming, the vast majority of fossil fuels—the biggest driver of climate change—have to be left in the ground. Fortunately, renewable energy alternatives are growing rapidly and a more competitive than ever; helping to shield the world from the worst climate risks, while improving human health, boosting our economies, and creating jobs.
Why Does it Matter?
Governments and scientists have agreed that global warming must remain under 2°C to avoid catastrophic climate change. The mean global temperature has already risen by almost a full degree since the start of the Industrial Revolution (c. 1750). At the United Nations climate talks in Paris in December 2015, governments acknowledged the growing threat of climate change and agreed to work towards keeping warming to 1.5°C.
The world can still avoid dangerous climate change, but action is needed urgently to cut emissions and to prepare communities and ecosystems for a hotter world.
People around the world are facing extreme weather. From more dangerous floods and storms, to droughts and heatwaves, extreme weather events are growing in frequency and intensity. We’re loading more and more heat into the air and seas, upping the risks, costing trillions of dollars, and mounting an even bigger toll on people, with the poorest the most exposed.
Climate change is a health emergency. Extremes of heat, more intense drought, ferocious storms, and more torrential downpours are already undermining human health and security. We risk undoing years of public health gains if we let global warming get away. Climate change and our continued dependence on dirty energy are polluting our air, increasing the spread of disease, fuelling food insecurity and malnutrition, and making water supplies scarcer and less safe. A world of more than 2°C would see an increasing number of people move across borders, exacerbate inequity, and raise the risk of conflict and social strife.
The oceans are warming and acidifying. People and wildlife depend on the healthy oceans: a vital source of livelihoods and sustenance. The oceans have absorbed most of extra heat and carbon dioxide (CO2) so far—more than the air—making the seas both warmer and more acidic. Warming waters are bleaching coral reefs and driving stronger storms. Rising ocean acidity threatens shellfish, including the tiny crustaceans without which marine food chains would collapse.
The ice is melting and the seas are rising. Sea ice in the Arctic is shrinking before our eyes with summer sea ice expected to virtually disappear before 2050. This would have dangerous consequences for global weather, not to mention degrade the region’s marvellous ecosystem. In the Antarctic and Arctic, massive ice shelves are disintegrating and breaking away. Glaciers are retreating at alarming rates worldwide, threatening a sea-level rise of several metres by century’s end.
Our ecosystems are in peril. As climate change wreaks havoc across the globe, ecosystems could undergo serious and irreversible changes, and even disappear altogether. The increase in average temperatures will see optimal habitats for many species move higher up mountains and further towards the poles. Where there is no higher ground or where changes are taking place too quickly, local losses or even global extinctions will follow.
How does this affect our Oceans?
The marine environment is already registering the impacts of climate change. The current increase in global temperature of 0.7°C since pre-industrial times is disrupting life in the oceans, from the tropics to the poles.
Marine species affected by climate change include plankton – which forms the basis of marine food chains – corals, fish, polar bears, walruses, seals, sea lions, penguins, and seabirds.
The Intergovernmental Panel on Climate Change predicts a further rise of between 1.4°C and 5.8°C by the end of the century. Climate change could therefore well be the knock-out punch for many species which are already under stress from overfishing and habitat loss.
The key impacts of climate change on the marine environment are…
One of the most visually dramatic effects of climate change is coral bleaching, a stress response caused by high water temperatures that can lead to coral death.
Recent years have seen widespread and severe coral bleaching episodes around the world, with coral mortality reaching 70% in some regions.
Most scientists believe that global warming will herald a new era of extreme and unpredictable weather.
Tropical storms and heavier rainfall may increase and so too would the consequent physical damage to coral reefs, other coastal ecosystems, and coastal communities. Hurricanes Hugo and Marilyn hit the US Virgin Islands National Park in 1989 and 1995, respectively, and did massive damage to coral ecosystems.
As the oceans warm, the location of the ideal water temperature may shift for many species.
A study has shown that fish in the North Sea have moved further north or into deeper water in response to rising sea temperatures. Other species may lose their homes for other reasons. The distribution of penguin species in the Antarctic Peninsula region, for example, is changing with reductions in sea ice due to global warming.
Rising temperatures can directly affect the metabolism, life cycle, and behaviour of marine species.
For many species, temperature serves as a cue for reproduction. Clearly, changes in sea temperature could affect their successful breeding.
The number of male and female offspring is determined by temperature for marine turtles, as well as some fish and copepods (tiny shrimp-like animals on which many other marine animals feed). Changing climate could therefore skew sex ratios and threaten population survival.
Rising sea levels
Global sea levels may rise by as much as 69cm during the next 100 years due to melting of glaciers and polar ice, and thermal expansion of warmer water.
Rising water levels will have serious impacts on marine ecosystems. The amount of light reaching offshore plants and algae dependent on photosynthesis could be reduced, while coastal habitats are already being flooded.
Rapid sea level rise will likely be the greatest climate change challenge to mangrove ecosystems, which require stable sea levels for long-term survival.
After absorbing a large proportion of the carbon dioxide released by human activities, the oceans are becoming acidic. If it weren’t for the oceans, the level of carbon dioxide in the atmosphere would be much higher.
The effect could be that fish, squid, and other gilled marine animals may find it harder to “breathe”, as the dissolved oxygen essential for their life becomes difficult to extract as water becomes more acidic. And shellfish, crabs, lobsters, and corals may find it more difficult to build their calcium carbonate shells. In some areas, calcium carbonate shells may even start to dissolve.