Climate Crisis: Sea Level ‘On Course To Rise By One Metre By 2100’ If Global Emissions Targets Are Missed

The Independent - Kate Ng

Projected ocean surge would 'devastate' coastal areas, researchers warn


NASA Scientific Visualisation Studio

Sea levels could rise by more than one metre by the year 2100 and 5m by 2300 if global emissions targets are not achieved, according to a study.

Scientists at Nanyang Technological University (NTU) in Singapore modelled projections from over 100 international experts for the global average sea level changes based on two climate scenarios.

In the low emissions scenario, in which global warming is limited to 2C above pre-industrial levels, experts estimate a rise of 0.5m by 2100 and 0.5m to 2m by 2300.

In a high emissions scenario where global warming rises by 4.5C, the estimates surged between 0.6m and 1.3m by 2100 and 1.7m to 5.6m by 2300.

The study, which was published in science journal Nature, notes that melting ice shelves in the Antarctic and Greenland ice sheets are the “largest potential contributors” to global mean sea level rise, as the biggest reservoirs of land-based ice on earth.

“Reference postulates that ice cliffs become unstable at elevations higher than 90 metres above sea level, facilitating the collapse of ice sheets during warm periods” the study states, noting that the Antarctic ice sheet is "particularly vulnerable to this process".

It adds: “The multimeter global mean sea level rise (GMSL) rise projected by some experts… would expose up to hundreds of millions of people to coastal flooding and devastate coastal ecosystems.

“However, the expert projections also clearly illustrate the potential for evading such large GMSL rise through successful reduction of emissions.”

The study was a collaboration between researchers from NTU, the University of Hong Kong, Maynooth University in Ireland, the UK's Durham University, Roward University and Tufts University in the US, and the Potsdam Institute for Climate Impact Research in Germany.

Professor Benjamin Horton, who led the survey, said: “The complexity of sea level projections, and the sheer amount of relevant scientific publications, make it difficult for policymakers to get an overview of the state of the science.

“To obtain this overview, it is useful to survey leading experts on the expected sea level rise, which provides a broader picture of future scenarios and informs policymakers so they can prepare necessary measures.”

Co-author Dr Andra Garner, an assistant professor of environmental science at Rowan University, said: “We now that the planet will see additional sea level rise in the future. But there are stark differences in the amount of sea level rise experts project for low emissions compared to high emissions.

“This provides a great deal of hope for the future, as well as a strong motivation to act now to avoid the more severe impacts of rising sea levels.”

Dr Niamh Cahill, of Maynooth University, added: “This international study is based on the informed opinions of 106 sea level experts and underlines the critical importance of pursuing a low emissions policy to limit sea level rise.”

Current global emissions targets under the Paris Agreement seek to limit global warming to 1.5C and aim to strengthen participating countries’ abilities to deal with the impact of climate change.

But a number of countries are not on track to meet their obligations, while Donald Trump has withdrawn the US - one of the world's leading carbon emitters - from the agreement entirely.

Links

• Scale of Greenland ice sheet melt is ‘off the charts’
• Before-and-after images show what US cities could look like in 2100
• Sea levels 'could be rising a centimetre a year' by 2100
• Sea level rise could make Earth ‘practically ungovernable’
• Sea ice 'to vanish from Arctic Ocean' as warming rate 'underestimated'
• North Pole 50 degrees hotter than usual in pre-Christmas heatwave
• Burning all fossil fuels ‘could cause global mass extinction’
• Unstable Antarctic glacier could cause seas to rise by three metres
• Sea levels set to ‘rise by more than a metre over next century’
• Seas 'could rise by more than a metre if global warming isn't tackled'
• Ice shelf on brink of collapse to compound risk of rising sea levels
• Melting Greenland ice sheet 'threatens coastal cities around world'
• Climate crisis to trigger debate over which cities to protect
• Global sea levels could rise more than two metres by 2100

Even If Climate Change Wasn't Happening, Phasing Out Coal Is A 'No-Regret' Solution

ScienceAlert -  Carly Cassella

John W Banagan/Stone/Getty Images

The benefits of phasing out coal far outweigh the real-world costs, scientists say, and that's the case even when climate change is left out of the equation entirely.

Of all the fossil fuels in the world, coal is the biggest source of carbon dioxide, and its impacts on air pollution and public health are profound.

Since the beginnings of the Industrial Revolution, large-scale coal burning has cost lives, yet we've been struggling to kick it. Our global reliance on coal runs deep, so deep that even though we know it's bad for us, we continue to burn it at unprecedented levels.

Now, new computer simulations on the regional effects of phasing out coal suggest that continuing on this trajectory is a big mistake, with negative impacts not only on the environment and human health, but also the economy.

"We're well into the 21st century now and still heavily rely on burning coal, making it one of the biggest threats to our climate, our health and the environment," says Sebastian Rauner who researches climate impacts at the Potsdam Institute for Climate Impact Research (PIK).

"That's why we decided to comprehensively test the case for a global coal exit: Does it add up, economically speaking? The short answer is: Yes, by far."

The simulation the team has created incorporates information on the full extent of a 'coal exit' scenario, accounting for air pollution as well as the impact on the energy sector as a whole.

Using this thorough modelling, researchers have now examined the direct and indirect effects of three different scenarios: one, where we meet our current emission-cutting pledges by 2030; another, where we limit global temperature rise by the end of the century to 2 °C through carbon pricing; and a third, where we almost completely phase out coal by 2050.

This, of course, would be a substantial transformation of the energy system as we know it, but it may well be worth it.

Monetising the environmental and human health costs for the first time - including how much it would cost to re-wild areas and invest in transforming our energy systems - the authors have come to a stunning 'no-regret' decision.

Cutting off our reliance on coal will be hugely beneficial for most regions in the world, even when you don't take into account the global benefits of slowing down climate change.

In the simulations, the effects on air pollution in the coal exit scenario are at almost similar levels to the 2 °C scenario, improving global public health exponentially, especially in Asia.

In fact, in almost all regions of the world, the direct policy cost of exiting coal was nothing compared to the human health and environmental benefits that will be reaped come 2050.

Only sub-Saharan Africa, Latin America and Japan faced higher costs than benefits, and the authors think that might be because air pollution isn't as much of a problem in these parts.

Under the scenario where nations put a price on carbon to limit a temperature rise to 2 °C, a somewhat scattered picture emerges. Asia benefits from improved air quality, while Europe, Japan, and the US save on policy costs. The rest of the world, however, falls short of reaping the same direct societal benefits.

But keep in mind, that's only for regional effects. The minute we zoom out and consider climate change on a global level, everyone appears to win.

"We find that, based on all countries' current climate pledges under the Paris Agreement, humanity is so far not on track to keep global warming below 2 degrees," says Rauner.

"Yet, if all countries would introduce coal exit policies, this would reduce the gap to fulfilling the goal by 50 percent worldwide. For coal-heavy economies like China and India, quitting coal would even close the gap by 80-90 percent until 2030."

The authors argue exiting coal is a particularly valuable strategy going forward, because it reduces carbon dioxide emissions at a relatively low cost while also reaping huge local benefits, such as a reduction in air pollution.

Still, even then, coal is just a start, or, as the authors say, a "crucial early entry point." Phasing out our use of it is a way to buy us some time so we can create further climate policies that turn us away from other fossil fuels and towards more renewable forms of energy. Exiting coal is not a solution to the whole problem.

"[A] holistic response to the climate and environmental crisis will eventually have to achieve almost full-scale decarbonization of power supply," the authors conclude, "and thus also entail a deep reduction of not only coal but also oil and gas and address non-electric energy demands in transportation, buildings and industry sectors as well as resource efficiency."

The study was published in Nature Climate Change.

Links

• Coal-exit health and environmental damage reductions outweigh economic impacts
• Your city could be exporting deadly air pollution – here’s why
• Air pollution may be damaging children’s brains – before they are even born
• Coal exit benefits outweigh its costs 
• The World Needs to Quit Coal. Why Is It So Hard?
• Air pollution in Victorian-era Britain – its effects on health now revealed
• Major Climate Report Describes a Strong Risk of Crisis as Early as 2040

Can Covid-19 Response Be A Model For Climate Action?

Lowy Institute - Noah Yim | Natasha Kassam

Mass behaviour change, policies guided by science, acting for the greater good: just what the climate crisis needs.

An empty street in San Francisco, 25 April (Liu Guanguan/China News Service via Getty Images)

In 2020, the world will see the largest annual drop in carbon dioxide emissions in history.

The havoc wreaked by the coronavirus and its accompanying lockdowns has seen fleets of planes grounded and factories shudder to a halt.

Levels of mobility in the world’s largest cities have fallen below 10% of usual traffic.

The International Energy Agency predicts that Covid-19 could wipe out international demand for coal, oil, and gas, with only renewable energy showing resilience.

The preliminary data from some of the world’s biggest economies shows that global emissions are in for a sharp, if temporary, decline. Early numbers from Europe suggest that the continent could see a 24% drop in EU Emissions Trading Scheme (ETS) emissions for the whole year. Global emissions will likely only fall by 5% – a reminder that most of the world’s emissions do not come from transportation.

But economies around the world are lifting their lockdowns. China, the world’s largest carbon emitter, saw a 25% decrease in emissions over its four-week lockdown. Factories in China are back online, and as in previous economic disruptions, stimulus packages and increased targets could outweigh the short-term impacts on energy and emissions.

With a few notable exceptions, most politicians and leaders are engaging in informed, rigorous discourse based on scientific advice. This is precisely the kind of discourse the climate crisis has lacked for so long.

Publics recognise the challenge ahead. In China, 87% say that climate change is as serious a crisis as Covid-19 in the long term. While the number in Australia is much lower, the majority – 59% – agree. Given the significant personal and economic sacrifices many publics have made to combat Covid-19, will these concerns finally translate into real progress in addressing climate change, once the current crisis has subsided?

The prospects look good. Covid-19 has put science front and centre. With a few notable exceptions, most politicians and leaders are engaging in informed, rigorous discourse based on scientific advice – whether about sending children to school or the need for onerous social-distancing guidelines. This is precisely the kind of discourse the climate crisis has lacked for so long – an ability to make effective socioeconomic policy arguments on the basis of sound scientific modeling.

And COVID-19 has been met with a resurgence in bipartisanship and political function in many parts of the world, the likes of which haven’t been seen in decades. There are conservative governments instituting utilitarian, Keynesian economic measures that social democrats like Bernie Sanders are praising. Spending bills of historic proportions are passing through legislatures as if they were uncontentious, everyday appropriation bills.

Finally, this pandemic has energised society into acting with consideration for greater public good. Despite the tragic but relatively low numbers of infections and deaths in Australia, the public has galvanised to comply with otherwise illiberal stay-at-home orders, out of recognition for public good.

Science, bipartisanship, and public will: we’re going to need all three to crest the climate crisis. It will need deep, complex engagement with genuinely difficult policy decisions based off rigorous scientific advice, paired with commitments from all political camps to rise above meaningless “gotcha” point-scoring, and acceptance from all members of society to incur relatively small costs today to avoid far greater ones tomorrow.

However, as has been the case in the past few years, this may be too much to ask in a post-coronavirus world. The 1918 flu pandemic has undoubtedly been the most frequently used historical analogy this year.

However, it did not receive this much attention in its immediate aftermath. Gina Kolata, in Flu, writes, “… the flu was expunged from newspapers, magazines, textbooks, and society’s collective memory. … the epidemic simply was so dreadful and so rolled up in people’s minds with the horrors of the war that most people did not want to think about it or write about it once the terrible year of 1918 was over.”

It is entirely possible that after the present pandemic is over, society will want to forget about it as quickly as possible. It is a perfectly understandable reaction. Already, a healthy appetite for escapism exists to distract us from the banality of every day.

So we may forget the overriding public good that we are all so diligently considering in our day-to-day behaviours. There may be antipathy towards wide-scale social mobilisation or aversion to governments calling upon society to incur even more costs for greater public good.

Furthermore, the low price of fossil fuels may see countries revert to less sustainable methods of energy generation to jump-start their economies, relegating the climate crisis to the bench in the name of economic restoration.

Nonetheless, Covid-19 will likely lead to permanent changes, whether in tax policy, the arts industry or the nature of work.

Will the post-Covid world see our rekindled respect for scientific fact, bipartisanship, and a more robust social contract help us confront climate change?

Or will crippling economic burdens and hard borders see more isolationism and environmental destruction for short-term economic benefit?

Some governments are already flagging the need to alter environmental standards to boost economic activity.

But business groups are suggesting that the rebuilding of virus-rattled economies can be done hand-in-hand with the transition to net-zero emissions.

Perhaps climate policy – historically relegated to the “too-hard” basket – stands a chance in the new world.

Links

• Planes grounded by coronavirus pandemic sit idle at airports around the world – in pictures 
• Citymapper Mobility Index: % of city moving compared to usual
• Oil Market Report - April 2020
• Global Energy Review 2020
• European power and carbon markets affected by COVID-19 – an early impact assessment
• Analysis: Coronavirus temporarily reduced China’s CO2 emissions by a quarter
• Australia will need to raise GST to pay coronavirus debt, tax expert says
• As we turn to creativity in isolation, the coronavirus is a calamity on top of an arts crisis
• Will COVID-19 ultimately change the way we work?
• ‘Cashed-up activists’ should not be able to hold up developments, Australia's resources minister says
• Australian businesses call for climate crisis and virus economic recovery to be tackled together