New Land Height Metric Raises Sea Level Rise Risk

New Land Height Metric Raises Sea Level Rise Risk

The reality of coastal flooding in Jakarta. Image: By Kompas/Hendra A Setyawan, via Climate Visuals

Millions of us now live in danger: we could be at risk from future high tides and winds, says a new approach to measuring land height.

Researchers have taken a closer look at estimates of coastal land height – and found that the numbers of people already at risk from sea level rise driven by global heating have multiplied threefold.

More than 100 million people already live below the high tide line, and 250 million live on plains that are lower than the current annual flood heights. Previous estimates have put these numbers at 28 million, and 65 million.

And even if the world takes immediate drastic action and reduces greenhouse gas emissions by the end of the century, at least 190 million people will find themselves below sea level.

If the world’s nations continue on the notorious business-as-usual track and go on burning ever greater volumes of fossil fuels, then around 630 million will, by the year 2100, find themselves on land that will be below the expected annual flood levels.

Protection in question

“These assessments show the potential of climate change to reshape cities, economies, coastlines and entire global regions within our lifetime,” said Scott Kulp of Climate Central, who led a study published in the journal Nature Communications.

“As the tideline rises higher than the ground people call home, nations will increasingly confront questions about whether, how much, and how long coastal defences can protect them.”

At the heart of the new research is a revised estimate of what constitutes sea level, and how it should be measured. Individuals and communities find out the hard way how the highest tides can rise to poison their farmlands with salt and wash away the foundations of their homes.

But the big picture – across nations and regions worldwide – is harder to estimate: for decades researchers have relied on satellite readings, confirmed by flights over limited spaces with radar equipment.

“There is still a great need for . . . more accurate elevation data. Lives and livelihoods depend on it”

But space-based readings by Nasa’s radar topography programme tend to be over-estimates, the researchers argue. That is because the technology measures the height of the first reflecting surface the radar signal touches. In open country, this may not matter. But forests and high buildings in densely-peopled cities distort the picture.

In parts of coastal Australia, and using a new approach, the researchers found that satellite readings delivered over-estimates of 2.5 metres. So global averages in the past have over-estimated, by around 2 metres, the elevation of lands that are home to billions.

Research of this kind helps clarify the challenge that faces governments, civic authorities and private citizens: communities grow up along low-lying coasts and estuaries because these provide good land, reliable water supplies and easy transport. But the catch with flood plains is that, sooner or later, they flood.

The repeated evidence of a decade of climate science is that floods will become more devastating, more frequent and more prolonged for a mix of reasons.

Multiple risks

Soils will subside because of the growing demand for groundwater and for clays and stone for bricks and mortar; because global average temperatures will rise and oceans expand as they warm; glaciers will melt and tip more water into the sea to raise ocean levels; and tropical cyclones will become more intense to drive more destructive storm surges.

Researchers have already warned that sea level rise could be accelerating, to bring more flooding to, for instance, the great cities of the US coasts, while some cities can expect ever more battering from Atlantic storms.

Coastal flooding is likely to create millions of climate refugees even within the US, and the worldwide costs of coastal flooding could reach $1 trillion a year by the end of the century.

The latest study confirms that the hazards are real, and may have so far been under-estimated. The researchers calculated that, in parts of China, Bangladesh, India, Vietnam and Thailand, places now home to 237 million people could face coastal flooding every year by 2050 – a figure 183 million higher than previous estimates.

US coasts threatened

The same study highlights faulty estimates of ground elevation even in the richest and most advanced nations. In some parts of the crowded coastal cities of New York, Boston and Miami, for instance, the researchers believe satellite readings have over-estimated ground height by almost five metres. They say their new approach reduces the margin of error to 2.5 cms.

Right now, around a billion people live on lands less than 10 metres above high tide levels. Around 250 million live within one metre above high tide.

“For all of the critical research that’s been done on climate change and sea level projections, it turns out that for most of the global coast we didn’t know the height of the ground beneath our feet,” said Benjamin Strauss, president and chief scientist of Climate Central, and co-author.

“Our data improves the picture, but there is still a great need for governments and insurance companies to produce and release more accurate elevation data. Lives and livelihoods depend on it.” – Climate News Network

About the Author

Tim Radford, freelance journalistTim Radford is a freelance journalist. He worked for The Guardian for 32 years, becoming (among other things) letters editor, arts editor, literary editor and science editor. He won the Association of British Science Writers award for science writer of the year four times. He served on the UK committee for the International Decade for Natural Disaster Reduction. He has lectured about science and the media in dozens of British and foreign cities. 

Science that Changed the World: The untold story of the other 1960s revolutionBook by this Author:

Science that Changed the World: The untold story of the other 1960s revolution
by Tim Radford.

Click here for more info and/or to order this book on Amazon. (Kindle book)

This Article Originally Appeared On Climate News Network

Related Books

Climate Change: What Everyone Needs to Know

by Joseph Romm
0190866101The essential primer on what will be the defining issue of our time, Climate Change: What Everyone Needs to Know® is a clear-eyed overview of the science, conflicts, and implications of our warming planet. From Joseph Romm, Chief Science Advisor for National Geographic's Years of Living Dangerously series and one of Rolling Stone's "100 people who are changing America," Climate Change offers user-friendly, scientifically rigorous answers to the most difficult (and commonly politicized) questions surrounding what climatologist Lonnie Thompson has deemed "a clear and present danger to civilization.". Available On Amazon

Climate Change: The Science of Global Warming and Our Energy Future second edition Edition

by Jason Smerdon
0231172834This second edition of Climate Change is an accessible and comprehensive guide to the science behind global warming. Exquisitely illustrated, the text is geared toward students at a variety of levels. Edmond A. Mathez and Jason E. Smerdon provide a broad, informative introduction to the science that underlies our understanding of the climate system and the effects of human activity on the warming of our planet.Mathez and Smerdon describe the roles that the atmosphere and ocean play in our climate, introduce the concept of radiation balance, and explain climate changes that occurred in the past. They also detail the human activities that influence the climate, such as greenhouse gas and aerosol emissions and deforestation, as well as the effects of natural phenomena.  Available On Amazon

The Science of Climate Change: A Hands-On Course

by Blair Lee, Alina Bachmann
194747300XThe Science of Climate Change: A Hands-On Course uses text and eighteen hands-on activities to explain and teach the science of global warming and climate change, how humans are responsible, and what can be done to slow or stop the rate of global warming and climate change. This book is a complete, comprehensive guide to an essential environmental topic. Subjects covered in this book include: how molecules transfer energy from the sun to warm the atmosphere, greenhouse gases, the greenhouse effect, global warming, the Industrial Revolution, the combustion reaction, feedback loops, the relationship between weather and climate, climate change, carbon sinks, extinction, carbon footprint, recycling, and alternative energy. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.

 

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook-icontwitter-iconrss-icon

 Get The Latest By Email

{emailcloak=off}

EVIDENCE

Ice On Earth’s Rivers Is In Rapid Decline
Ice On Earth’s Rivers Is In Rapid Decline
by InnerSelf Staff
The amount of ice in the Earth’s rivers has declined rapidly over the past three decades, and the trend is likely to…
Climate Watchdog Warns US Fracking Boom Leading to 30% Rise in Greenhouse Gas Emissions by 2025
Climate Watchdog Warns US Fracking Boom Leading to 30% Rise in Greenhouse Gas Emissions by 2025
by Jessica Corbett
This analysis shows that we're heading in the wrong direction and really need to slow emissions growth from the oil,…
Daily Weather Now Shows Climate Change’s Fingerprints
Daily Weather Now Shows Climate Change’s Fingerprints
by InnerSelf Staff
Climate researchers can now detect the fingerprint of global warming in daily weather observations at the global scale.
Our Climate Is Like Reckless Banking Before The Crash – It's Time To Talk About Near-term Collapse
Our Climate Is Like Reckless Banking Before The Crash – It's Time To Talk About Near-term Collapse
by Aled Jones and Will Steffen
After a quarter of a century of nations from around the world coming together to discuss progress in dealing with…
Racing Ice Loss Strips Greenland Of Mass
Racing Ice Loss Strips Greenland Of Mass
by Tim Radford
Greenland is shrinking, losing ice seven times faster than a generation ago. Scientists have taken a new and ominous…
Americans Are Worried About Climate Change, But Underestimate How Serious It Is
Americans Are Worried About Climate Change, But Underestimate How Serious It Is
by Bobby Duffy
The world is often better and getting better than people think. Murder rates, deaths from terrorism and extreme poverty…
Fossil Fuel Production Plans Could Push Earth off a Climate Cliff
by The Real News Network
The United Nations is beginning its climate summit in Madrid.
UN Report Warns Only Rapid and Transformational Action Can Stave Off Global Climate Disaster
UN Report Warns Only Rapid and Transformational Action Can Stave Off Global Climate Disaster
by Jake Johnson
Failure to heed these warnings and take drastic action to reverse emissions means we will continue to witness deadly…

LATEST VIDEOS

The Rise Of Solar Power
by CNBC
Solar power is on the rise. You can see the evidence on rooftops and in the desert, where utility-scale solar plants…
World's Largest Batteries: Pumped Storage
by Practical Engineering
The vast majority of our grid-scale storage of electricity uses this clever method.
Hydrogen Fuels Rockets, But What About Power For Daily Life?
Hydrogen Fuels Rockets, But What About Power For Daily Life?
by Zhenguo Huang
Have you ever watched a space shuttle launch? The fuel used to thrust these enormous structures away from Earth’s…
Fossil Fuel Production Plans Could Push Earth off a Climate Cliff
by The Real News Network
The United Nations is beginning its climate summit in Madrid.
Big Rail Spends More on Denying Climate Change than Big Oil
by The Real News Network
A new study concludes that rail is the industry that's injected the most money into climate change denial propaganda…
Did Scientists Get Climate Change Wrong?
by Sabine Hossenfelder
Interview with Prof Tim Palmer from the University of Oxford.
The New Normal: Climate Change Poses Challenges For Minnesota Farmers
by KMSP-TV Minneapolis-St. Paul
Spring brought a deluge of rain in southern Minnesota and it never seemed to stop.
Report: Today's Kids' Health Will Be Imperiled by Climate Change
by VOA News
An international report from researchers at 35 institutions says climate change will threaten the health and quality of…

LATEST ARTICLES

Can Sea Water Desalination Save The World?
by CNBC
Today, one out of three people don’t have access to safe drinking water. And that’s the result of many things, but one…
The Rise Of Solar Power
by CNBC
Solar power is on the rise. You can see the evidence on rooftops and in the desert, where utility-scale solar plants…
World's Largest Batteries: Pumped Storage
by Practical Engineering
The vast majority of our grid-scale storage of electricity uses this clever method.
How Wildfire Smoke AfHow Wildfire Smoke Affects Pets And Other Animals
How Wildfire Smoke Affects Pets And Other Animals
by Stephanie Laura Bond, et al
Catastrophic fires across the globe are increasing in both frequency and magnitude. The bushfires in Australia, fuelled…
5 Ways Families Can Help Tackle Climate Change
5 Ways Families Can Help Tackle Climate Change
by Greg McDermid, et al
While many climate solutions require leadership from governments, we also need changes within regular households, which…
Geo-engineering Could Make Poor Countries Richer
Geo-engineering Could Make Poor Countries Richer
by Tim Radford
There is still no certainty that geo-engineering could save the world. But, paradoxically, if it did work it might…
Worst Marine Heatwave On Record Killed One Million Seabirds In North Pacific Ocean
Worst Marine Heatwave On Record Killed One Million Seabirds In North Pacific Ocean
by Tim Birkhead
A common guillemot colony on the Farallon Islands, California. Duncan Wright/Wikipedia, CC BY-SA The common guillemot…
Nuclear Power Cannot Rival Renewable Energy
Nuclear Power Cannot Rival Renewable Energy
by Paul Brown
Far from tackling climate change, nuclear power is an expensive distraction whose safety is threatened by wildfires and…