Climate report says intense storms and loss of marine life are already inevitable
 |
| A child walks through floodwaters near a pier in California. The climate crisis can expose millions to flooding. Photograph: Ana Venegas/AP |
Quick guide
The IPCC report in numbers
5.4 metres: highest likely sea level rise by 2300, if global carbon emissions are not cut.
653bn tonnes: average ice melted in Greenland, Antarctica and
mountain glaciers every year from 2006-2016, equivalent to 500 Olympic
swimming pools every minute.100-1,000 times: the increase in coastal flood damages expected in 2100 unless major adaptation efforts are made. 1.8 billion people: the number likely to be directly affected by sea level rise on low-lying coasts and melting glaciers in high mountain regions in 2050. 1,500bn tonnes: the carbon stored in permafrost, almost double all the carbon in the atmosphere. 7,000: the number of scientific articles considered by the 104 expert authors from 36 countries. |
The stark assessment of the climate crisis in the world’s oceans and ice caps concludes that many serious impacts are already inevitable, from more intense storms to melting permafrost and dwindling marine life.
But far worse impacts will hit without urgent action to cut fossil fuel emissions, including eventual sea level rise of more than 4 metres in the worst case, an outcome that would redraw the map of the world and harm billions of people.
The report from the Intergovernmental Panel on Climate Change (IPCC), and approved by its 193 member nations, says that “all people on Earth depend directly or indirectly on the ocean” and ice caps and glaciers to regulate the climate and provide water and oxygen. But it finds unprecedented and dangerous changes being driven by global heating.
Sea level rise is accelerating as losses from Greenland and Antarctica increase, and the ocean is getting hotter, more acidic and less oxygenated. All these trends will continue to the end of the century, the IPCC report said.
Half the world’s megacities, and almost 2 billion people, live on coasts. Even if heating is restricted to just 2C, scientists expect the impact of sea level rise to cause several trillion dollars of damage a year, and result in many millions of migrants.
“The future for low-lying coastal communities looks extremely bleak,” said Prof Jonathan Bamber at Bristol University in the UK, who is not one of the report’s authors. “But the consequences will be felt by all of us. There is plenty to be concerned about for the future of humanity and social order from the headlines in this report.”
The new IPCC projections of likely sea level rise by 2100 are higher than those it made in 2014, due to unexpectedly fast melting in Antarctica. Without cuts in carbon emissions, the ocean is expected to rise between 61cm and 110cm, about 10cm more than the earlier estimate. A 10cm rise means an additional 10 million people exposed to flooding, research shows.
 |
| An iceberg floating in Antarctica’s McMurdo Sound. Photograph: Chris Larsen/AFP/Getty Images |
Even if huge cuts in emissions begin immediately, between 29cm and 59cm of sea level rise is already inevitable because the ice caps and glaciers melt slowly. Sea level will rise for centuries without action, Sebesvari warned. “The dramatic thing about sea level rise is if we accept 1 metre happening by 2100, we accept we will get about 4 metres by 2300. That is simply not an option we can risk.”
Extreme sea level impacts will be felt in many places very soon and well before 2050, Sebesvari said. The IPCC report states: “Extreme sea level events that [occur] once per century in the recent past are projected to occur at least once per year at many locations by 2050 in all scenarios.”
The heating oceans are causing more intense tropical storms to batter coasts, the IPCC report found, with stronger winds and greater deluges of rain. For example, Hurricane Harvey’s unprecedented deluge, which caused catastrophic flooding, was made three times more likely by climate change.
Ocean heating also harms kelp forests and other important ecosystems, with the marine heatwaves that sear through them like underwater wildfires having doubled in frequency in the last 40 years. They are projected to increase by at least 20 times by 2100, the IPCC reported.
 |
| Floodwaters in Houston after Hurricane Harvey struck the US. Photograph: David J. Phillip/AP |
Q&A
What is the IPCC?
The Intergovernmental Panel on Climate Change (IPCC)
is a body of the United Nations.Based in Geneva, it was established in 1988 by the World Meteorological Organization and the United Nations Environment Programme to determine the state of knowledge on climate change.
For each report, the IPCC assembles hundreds of senior scientists
from across the world to assess the current state of knowledge.
It publishes major 'assessment' reports every 5–7 years, with the next, 'AR6' due in 2022, as well as producing ad hoc special reports. The IPCC has more than 190 member countries, and its reports are drafted and reviewed in several stages to guarantee their quality, with member governments signing off the final versions. The "Principles Governing IPCC Work" states it will assess:
|
The world’s high mountain glaciers, upon which almost 2 billion people rely for water, are also melting fast, the IPCC found, while landslides are expected to increase. A third of the great Himalayan range is already doomed, with two-thirds projected to vanish if emissions are not cut.
One of the most worrying alarms sounded by the IPCC report is about melting tundra and increasing wildfires in northern latitudes: “Widespread permafrost thaw is projected for this century and beyond.” A quarter is already near certain to melt, it said, and 70% or more would go if emissions are not curbed. In the latter case, hundreds of billions of tonnes of carbon dioxide and methane could be released, supercharging the climate emergency.
“That risks taking us beyond the point where climate change could be easily constrained,” said Richard Black, at the UK’s Energy and Climate Intelligence Unit. “Nevertheless, the IPCC’s 2018 report concluded that governments can shrink emissions quickly enough to keep global warming to 1.5C if they choose. None can claim to be unaware of both the dangers of untrammelled climate change nor the feasibility of preventing it.”
Anne Hidalgo, the mayor of Paris and chair of the C40 Cities climate coalition, said the IPCC report was shocking. “Around 1.9 billion people and over half of the world’s megacities are all in grave danger if we don’t act immediately. Several cities, home to hundreds of thousands of people, are already disappearing underwater. This is what the climate crisis looks like now.”
Taehyun Park, of Greenpeace East Asia, said: “The science is both chilling and compelling. The impacts on our oceans are on a much larger scale and happening way faster than predicted. It will require unprecedented political action to prevent the most severe consequences to our planet.”
As well as cutting fossil fuel emissions, preparing for the inevitable impacts is also vital, said Sebesvari, especially in poorer nations that lack the funds to build sea walls, move settlements or restore protective coastal marshes.
“Action is needed now to secure the coast for our children and coming generations,” she said. The pressure now being exerted by the global school strikes for climate was important, she said. “I have very strong motivation. I have two kids and we are really being tested by our kids on our actions.”
Links
- Scott Morrison says Australia's record on climate change misrepresented by media
- Albanese says Scott Morrison has a habit of being 'loose with the truth'
- A third of Himalayan ice cap doomed, finds report
- ‘Extraordinary thinning’ of ice sheets revealed deep inside Antarctica
- Global heating: London to have climate similar to Barcelona by 2050'Tipping points' could exacerbate climate crisis, scientists fear
- World leaders 'have moral obligation to act' after UN climate report
- We have 12 years to limit climate change catastrophe, warns UN
- IPCC report: climate change felt 'on all continents and across the oceans'
- IPCC vice-chair: Attacks on climate science echo tobacco industry tactics
- Rajendra Pachauri: Climate scientists face 'new form of persecution'
- UN to commission independent scientific inquiry into IPCC
No comments :
Post a Comment