Climate change impacts will increase if nothing is done to reduce greenhouse gas emissions. Those impacts will include changes to the world’s oceans.
Oceans cover 71 percent of the earth’s surface and contain around 97 percent of the earth’s water. Climate change is already affecting the oceans. “Pervasive ocean and cryosphere changes…are already being caused by human-induced climate change,” the latest report by the UN’s Intergovernmental Panel on Climate Change (IPCC) declares. The cryosphere are frozen components of the earth’s surface. The rate of ocean warming has more than doubled since 1993.
Around 10 percent of the earth’s surface is covered by ice sheets or glaciers. Climate change has caused “widespread shrinking of the cryosphere, with mass loss from ice sheets and glaciers, reductions in snow cover and Arctic sea ice extent and thickness, and increased permafrost temperature,” according to the report.
“If we reduce emissions sharply, consequences for people and their livelihoods will still be challenging, but potentially more manageable for those who are most vulnerable,” Hoesung Lee, Chair of the IPCC. “We increase our ability to build resilience and there will be more benefits for sustainable development.”
How rising sea level and loss of ice will impact people
Rising sea levels and cryosphere decline affect people. A total of 680 million people live in low-lying coastal zones and 670 million people in high mountain regions. Four million people permanently live in the Arctic region and 65 million people live in small island developing states. Sea level rise will increase the frequency of sea level events such as high tides and intense storms. Some island nations may not be habitable due to sea level rise.
Glaciers could lose a fifth of their mass in this century even if emissions are low, and in regions such as Central Europe, they could lose over 80 percent. There is “very high confidence” that Arctic sea ice has shrunk during all months of the year and about half of the summer loss is caused by climate change. The melting of glaciers and permafrost and the decline of snow and ice will increase hazards for people living in mountain regions, including landslides, avalanches, rockfalls, and floods.
Under high emission scenarios, small glaciers in Europe, eastern African, the Andes, and Indonesia are projected to lose over 80 percent of their current ice mass by 2100. The loss of high mountain cryosphere will affect recreational activities, tourism, and cultural assets. As mountain glaciers retreat, water availability and quality changes, which has implications for sectors such as agriculture and hydropower.
Marine life is affected by climate change
Marine life is already being disrupted by warming and changes in ocean chemistry. The ocean has taken up over 90 percent of the excess heat in the climate system, and by 2100 the ocean will take up to two to four times more heat than between 1970 and now if global temperature rise is not limited to two degrees Celsius. Ocean warming results in less mixing between water layers and causes the supply of oxygen and nutrients for marine life to decline. Ocean acidification is occurring. The ocean has taken up twenty to thirty percent of carbon dioxide emissions since the 1980s which causes ocean acidification.
“The science is both chilling and compelling,” said Taehyun Park, global climate political advisor with Greenpeace East Asia. “The impacts of human-made carbon emissions on our oceans are on a much larger scale and happening way faster than predicted.”
The time is now to take action
The world’s governments can do something to protect oceans. They can adopt a Global Ocean Treaty. After all, almost 50 percent of the planet is covered by international waters. “Anything short of a mechanism capable of providing real protection to our planet’s critical carbon sinks, is a failure to respond to the millions of climate strikers around the world who came out onto the streets demanding radical change,” as Arlo Hemphill with Greenpeace USA said.
The world’s governments can also take strong action to reduce greenhouse gas emissions. They can listen to the pleadings of people who recently took part in a global climate strike. There is no time to waste. Life as we know it for the inhabitants of this planet is at stake.