A major new United Nations report warns that climate change is devastating our seas and frozen regions as never before. A UN panel of scientists have determined that waters are rising, the ice is melting, and species are moving habitat due to human activities. Besides the loss of permanently frozen lands threatens to release even more carbon, hastening the decline. There is some hope that the worst impacts can be avoided with extreme and immediate cuts to carbon emissions.
This report is the third in a series of special studies that have been submitted by the Intergovernmental Panel on Climate Change (IPCC) over the past 12 months. The scientists earlier looked at how the world would cope if temperatures rose by 1.5C by the end of this century and also reported on how the lands of the Earth would be affected by climate change.
But, this new study focusses on the impact of rising temperatures on our oceans and frozen regions and is perhaps the most worrying and depressing of the three.
What Have They Found And How Bad Is It?
In short, the water on our planet is getting warmer, the world’s ice is melting rapidly, and both have implications for nearly every living thing on the planet.
Dr. Jean-Pierre Gattuso, a coordinating lead author of the report, said, “The blue planet is in serious danger right now, suffering many insults from many different directions and it’s our fault”.
The experts are “virtually certain” that the global ocean has now warmed without a break since 1970.
The waters have absorbed more than 90% of the extra heat generated by humans over the last decades, and the rate at which it has soaked up this heat has doubled since 1993. The seas were once rising mainly due to thermal expansion and that extra energy made the water molecules move around more, causing them to take up more space. But the IPCC finds that now the rising water levels are being principally by driven the melting of Greenland and Antarctica.
Due to warming, the loss of ice mass from the Antarctic ice sheet in the years between 2007 and 2016 has tripled compared to the 10 years before that. Greenland witnessed a doubling of mass loss over the same period. The report supposes this will continue throughout the 21st Century and beyond.
Glaciers in areas such as the tropical Andes, Central Europe, and North Asia are that projected to lose 80% of their ice by 2100 under a high carbon emissions setting, which is expected to have huge consequences for millions of people.
Implications Of All This Melting Ice
All the extra water gushing into the seas is rising up the average ocean water levels around the world and is expected to continue over the decades to come.
This latest report says that global average sea levels could surge by up to 1.1m by 2100, in the worst warming scenario. This is a higher than 10cm from previous IPCC projections because of the larger ice loss now happening in Antarctica.
Dr. Jean-Pierre Gattuso, from the CNRS, France’s national science agency, said, “What surprised me the most is the fact that the highest projected sea level rise has been revised upwards and it is now 1.1 metres. This will have widespread consequences for low lying coasts where almost 700 million people live and it is worrying.”
Most of the city of Hull located on the east coast of England lies below the level of a typical high tide. The sea in such locations can be both a source of wealth and a threat to life.
So the conclusions of the IPCC report have actual connotations. Computer simulations that were developed by the University of Hull, show that if the level of the ocean rises by just one meter, the center of the city will be safe but neighboring areas will go under. This poses a painful question for all low-lying places the world over: which should be saved and which should be abandoned as the waters rise?
The report clearly says that some island states are likely to become uninhabitable after 2100. The scientists also recommend relocating people away from threatened communities is worth considering “if safe alternative localities are available”.
Effect on Humans
One of the key messages from the report is that the warming of the oceans and cryosphere on land is part of a chain of poor outcomes that will possibly affect millions of people well into the future. In higher emissions circumstances, even wealthy megacities like New York or Shanghai as well as large tropical agricultural deltas like the Mekong will face high or very high risks from sea-level rise. The report states that a world with severely increased levels of warm water will inline give rise to big increases in horrid and dangerous weather events like surges from tropical cyclones.
The study states that even if future emissions of carbon are curbed significantly, “Extreme sea-level events that are historically rare (once per century in the recent past) are projected to occur frequently (at least once per year) at many locations by 2050”.
Prof Debra Roberts, a co-chair of an IPCC working group II, said, “What we are seeing now is enduring and unprecedented change. Even if you live in an inland part of the world, the changes in the climate system, drawn in by the very large changes in the ocean and cryosphere are going to impact the way you live your life and the opportunities for sustainable development.”
Effects on us can be far-reaching as flood damage could rise by two or three orders of magnitude. The acidification of the oceans owing to increased levels of CO2 is threatening corals, to such an extent that even at 1.5°C of warming, 90% might disappear. CO2 dissolves in water to form carbonic acid. So, as more carbon dioxide dissolves in our oceans, the more acidic it gets. Species of fish will need to move as ocean temperatures continue to rise. Seafood safety could get compromised because it might expose humans to increased levels of mercury and persistent organic pollutants in marine plants and animals. These pollutants are produced from the same fossil fuel burning that releases the climate-warming gas CO2.
Our capacity to generate electricity may get impaired as warming melts the glaciers, shifting the availability of water for hydropower. Huge amounts of carbon that are stored in the permanently frozen regions of the world like Siberia and Northern Canada are likely to change dramatically and nearly 70% of the near-surface permafrost is expected to thaw if emissions continue to rise.
The biggest worry is that this could release “tens to hundreds of billions of tonnes” of CO2 and methane to the atmosphere by 2100 which would be a crucial limitation on our ability to limit global warming in the centuries to come.
Long Term Effects
What happens in the future is dependent on what is done in the near term to limit emissions. Though, there are some warnings in the report that certain changes may not be easily undone. Data from Antarctica project the onset of “irreversible ice sheet instability” which could see a sea-level rise by several meters within centuries.
Dr Nerilie Abram from the Australian National University in Canberra, who’s a contributing lead author on the report, said, “We give this sea level rise information to 2300, and the reason for that is that there is a lot of change locked in, to the ice sheets and the contribution that will have to sea level rise. So even in a scenario where we can reduce greenhouse gases, there are still future sea level rise that people will have to plan for.”
Significant and irreversible loses of cultural knowledge is also anticipated as fish species that indigenous communities depend on may move to escape warming.
Some Guarded Hope
The ominous report does present a strong play of the fact that the future of our oceans is still in our hands. The method is well worn by now as first recommended by the IPCC report last year, of deep, rapid cuts in carbon emissions.
Hoesung Lee, chair of the IPCC, said, “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”.
Truly, some scientists involved in the report are certain that public pressure on politicians is a crucial part of increasing ambition.
Dr. Jean-Pierre Gattuso said, “After the demonstrations of young people last week, I think they are the best chance for us. They are dynamic, they are active I am hopeful they will continue their actions and they will make society change.”