Sea levels could rise by up to FOUR FEET by the end of the century

Sea levels could rise by up to FOUR FEET by the end of the century if Earth warms by another 7°F – endangering hundreds of millions of coastal dwellers

  • Researchers say estimates for sea level rise don’t consider melting ice sheets 
  • With this taken into account trillions of tonnes of mass could be shed by 2100 
  • This will cause a serious rise in sea levels around the world putting lives at risk
  • This is based on the ‘real possibility’ temperatures could rise by 7 degrees Fahrenheit over the next century which is almost double the UN target of 3.6F 

Sea levels around the world could rise by more than 4ft by the end of the century, if temperatures rise by another 7F, study finds, putting millions of lives at risk. 

The impact of global warming on ice sheets covering West Antarctica and Greenland has been underestimated, warn scientists from Imperial College London. 

Lead author Professor Martin Siegert, said greenhouse gas emissions were still on the rise and so strong heating of 7F by 2100 is ‘well within the realm of the possible’. 

A new study, published in the journal One Earth, predicts these ice sheets will shed trillions of tonnes in mass if temperatures rise by 7 degrees F over the next century.

This will leave the world’s flood barriers insufficient, endangering hundreds of millions of people living in low lying and coastal communities around the world. 

Their predictions are based on an analysis of previous periods of natural climate change that found ice sheets responded to warming by rapidly losing mass at rates that at times were higher than currently observed. 

A new study, published in the journal One Earth, predicts these ice sheets will shed trillions of tonnes in mass if temperatures rise by 7 degrees F over the next century 

The team reviewed models of the effect on ice sheets that the Intergovernmental Panel on Climate Change (IPCC) 2019 report relies on to calculate ‘worst case scenario’ climate predictions by 2100.

For the ‘strong heating’ scenario, it gave a ‘likely’ rise of between 2ft and 3.6ft above 1950 sea levels, but Imperial researchers say it could be double the likely scenario.

The latest analysis found the simulations do not include sufficient detail on key processes that may lead to drastic melting in this event.

These include interactions with warming oceans and how the ice fractures and breaks apart which would mean the true picture is more likely to be above the IPCC range rather than below it.   

The team say more effort should be put into gathering and recording data from ice sheets, including historical data, to create an ‘early warning system’ for sea rises. 

The team’s analysis showed that ice sheet models do not include sufficient detail on key processes that may lead to significant ice sheet mass loss, suggesting it will have a much greater impact on sea levels than officials predict

‘Currently, hundreds of millions of people live in regions susceptible to coastal flooding, and the likelihood of even worse flooding will significantly increase with severe sea level rise,’ said Siegert.

‘The sea level rise we have already faced has been somewhat mitigated by flood barriers and other measures, but we are unprepared for higher rates of rise that could overwhelm these measures.

‘If we don’t do more to avert dangerous global heating, we may reach a point where we can no longer protect people.’

Understanding the way strong global warming affects polar ice sheets will be crucial to projections over the next century. But uncertainties remain, say the researchers.

Throughout the 20th century, rising seas have been dominated by a phenomenon called ‘thermal expansion’ – a process where added heat drives water molecules apart, swelling the volume of the ocean. 

It made forecasting relatively simple using relationships between the temperature and the expansion but this century a second mechanism has dominated.

This is the addition of water from melting ice sheets and glaciers that made predicting ocean levels ‘more of a guessing game’ as they respond to global warming in complex and connected ways. 

Last year US scientists found up to 630 million people are living on land prone to flooding by the end of the century – three times more than previously thought.

The team suggest a number of measures could be introduced to create an early warning system for ice loss to help predict future sea level rises more accurately – including mapping subglacial regions, collecting ocean data and examining past changes

Co-author John Englander, president of the Rising Seas Institute, said: ‘Sea level rise will be one of the most challenging issues faced by society in the coming decades.

‘We need to recognise we cannot stand by and wait for clarity about actual sea level rise to begin planning for it,’ added Englander.

‘Waiting for better confidence in predictions is not a reason to delay building a margin of safety, for example into building codes and zoning, recognising the inevitability of sea level rise and its catastrophic implications.’

Experts looking ahead to the next century often look back at previous episodes of natural climate change for clues as to how various Earth systems will react.

Martin Siegart (pictured) and his team examined the impact of melting glaciers by examining past episodes of natural climate change and found their impact was being under estimated

Doing so can help shed light on the increasing impact of climate change on human society, nature and the environment.

For example, at the end of the last glacial period 10,000 years ago there is evidence ice sheets disappeared quicker than we are observing today.

Sea levels rose several feet each century – suggesting current calculations are being set worryingly low. They may vanish faster in the next decades than is feared.

The new Imperial study says the estimates of sea level rises could be made more accurate with better mapping of the ground beneath glaciers and ice sheets.

The collection of data at the margin where they meet the ocean, and improved computer models of the atmosphere, oceans and ice sheets, would also help.

Co-author John Englander (pictured), president of the Rising Seas Institute, said: ‘Sea level rise will be one of the most challenging issues faced by society in the coming decades’

These steps would offer hope of a next-generation ‘early warning system’ focused on signals of rapid change, such as increases in ocean water temperature along the margins of ice sheets.

Siegert added: ‘We already have a good start on an early warning system for dangerous sea-level rise, with satellites, airborne platforms, robotic devices, field investigators and expert knowledge.

‘While this network is growing and getting stronger, it has major weaknesses at ice sheet boundaries that require urgent action.

‘We need to develop an array of robotic devices in key parts of Antarctica and Greenland that are most vulnerable and capable of rapid sea level rise in the future.’

The Paris climate treaty’s goal is to keep global warming below 3.6°C by 2100. This would still result in rising seas but not to the extent predicted by this study.   

The findings have been published in the journal One Earth.

Revealed: MailOnline dissects the impact greenhouse gases have on the planet – and what is being done to stop air pollution


Carbon dioxide

Carbon dioxide (CO2) is one of the biggest contributors to global warming. After the gas is released into the atmosphere it stays there, making it difficult for heat to escape – and warming up the planet in the process. 

It is primarily released from burning fossil fuels such as coal, oil and gas, as well as cement production. 

The average monthly concentration of CO2 in the Earth’s atmosphere, as of April 2019, is 413 parts per million (ppm). Before the Industrial Revolution, the concentration was just 280 ppm. 

CO2 concentration has fluctuated over the last 800,000 years between 180 to 280ppm, but has been vastly accelerated by pollution caused by humans. 

Nitrogen dioxide 

The gas nitrogen dioxide (NO2) comes from burning fossil fuels, car exhaust emissions and the use of nitrogen-based fertilisers used in agriculture.

Although there is far less NO2 in the atmosphere than CO2, it is between 200 and 300 times more effective at trapping heat.

Sulfur dioxide 

Sulfur dioxide (SO2) also primarily comes from fossil fuel burning, but can also be released from car exhausts.

SO2 can react with water, oxygen and other chemicals in the atmosphere to cause acid rain. 

Carbon monoxide 

Carbon monoxide (CO) is an indirect greenhouse gas as it reacts with hydroxyl radicals, removing them. Hydroxyl radicals reduce the lifetime of carbon dioxide and other greenhouse gases. 


What is particulate matter?

Particulate matter refers to tiny parts of solids or liquid materials in the air. 

Some are visible, such as dust, whereas others cannot be seen by the naked eye. 

Materials such as metals, microplastics, soil and chemicals can be in particulate matter.

Particulate matter (or PM) is described in micrometres. The two main ones mentioned in reports and studies are PM10 (less than 10 micrometres) and PM2.5 (less than 2.5 micrometres).

Air pollution comes from burning fossil fuels, cars, cement making and agriculture 

Scientists measure the rate of particulates in the air by cubic metre.

Particulate matter is sent into the air by a number of processes including burning fossil fuels, driving cars and steel making.

Why are particulates dangerous?

Particulates are dangerous because those less than 10 micrometres in diameter can get deep into your lungs, or even pass into your bloodstream. Particulates are found in higher concentrations in urban areas, particularly along main roads. 

Health impact

What sort of health problems can pollution cause?

According to the World Health Organization, a third of deaths from stroke, lung cancer and heart disease can be linked to air pollution. 

Some of the effects of air pollution on the body are not understood, but pollution may increase inflammation which narrows the arteries leading to heart attacks or strokes. 

As well as this, almost one in 10 lung cancer cases in the UK are caused by air pollution. 

Particulates find their way into the lungs and get lodged there, causing inflammation and damage. As well as this, some chemicals in particulates that make their way into the body can cause cancer. 

Deaths from pollution 

Around seven million people die prematurely because of air pollution every year. Pollution can cause a number of issues including asthma attacks, strokes, various cancers and cardiovascular problems. 


Asthma triggers

Air pollution can cause problems for asthma sufferers for a number of reasons. Pollutants in traffic fumes can irritate the airways, and particulates can get into your lungs and throat and make these areas inflamed. 

Problems in pregnancy 

Women exposed to air pollution before getting pregnant are nearly 20 per cent more likely to have babies with birth defects, research suggested in January 2018.

Living within 3.1 miles (5km) of a highly-polluted area one month before conceiving makes women more likely to give birth to babies with defects such as cleft palates or lips, a study by University of Cincinnati found.

For every 0.01mg/m3 increase in fine air particles, birth defects rise by 19 per cent, the research adds. 

Previous research suggests this causes birth defects as a result of women suffering inflammation and ‘internal stress’. 

What is being done to tackle air pollution? 

Paris agreement on climate change

The Paris Agreement, which was first signed in 2015, is an international agreement to control and limit climate change. 

It hopes to hold the increase in the global average temperature to below 2°C (3.6ºF) ‘and to pursue efforts to limit the temperature increase to 1.5°C (2.7°F)’.

Carbon neutral by 2050 

The UK government has announced plans to make the country carbon neutral by 2050. 

They plan to do this by planting more trees and by installing ‘carbon capture’ technology at the source of the pollution.

Some critics are worried that this first option will be used by the government to export its carbon offsetting to other countries.

International carbon credits let nations continue emitting carbon while paying for trees to be planted elsewhere, balancing out their emissions.

No new petrol or diesel vehicles by 2040

In 2017, the UK government announced the sale of new petrol and diesel cars would be banned by 2040.  

However,  MPs on the climate change committee have urged the government to bring the ban forward to 2030, as by then they will have an equivalent range and price.

The Paris Agreement, which was first signed in 2015, is an international agreement to control and limit climate change. Pictured: air pollution over Paris in 2019.

Norway’s electric car subsidies

The speedy electrification of Norway’s automotive fleet is attributed mainly to generous state subsidies. Electric cars are almost entirely exempt from the heavy taxes imposed on petrol and diesel cars, which makes them competitively priced.

A VW Golf with a standard combustion engine costs nearly 334,000 kroner (34,500 euros, $38,600), while its electric cousin the e-Golf costs 326,000 kroner thanks to a lower tax quotient. 

Criticisms of inaction on climate change

The Committee on Climate Change (CCC) has said there is a ‘shocking’ lack of Government preparation for the risks to the country from climate change. 

The committee assessed 33 areas where the risks of climate change had to be addressed – from flood resilience of properties to impacts on farmland and supply chains – and found no real progress in any of them.

The UK is not prepared for 2°C of warming, the level at which countries have pledged to curb temperature rises, let alone a 4°C rise, which is possible if greenhouse gases are not cut globally, the committee said.

It added that cities need more green spaces to stop the urban ‘heat island’ effect, and to prevent floods by soaking up heavy rainfall. 

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