“With continued growth in emissions at historic rates, annual losses in some economic sectors are projected to reach hundreds of billions of dollars by the end of the century — more than the current gross domestic product (GDP) of many US states,” the latest edition of the National Climate Assessment said.

“Without substantial and sustained global mitigation and regional adaptation efforts, climate change is expected to cause growing losses to American infrastructure and property and impede the rate of economic growth over this century,” it added.

The effects will spill over into global trade, affecting import and export prices and US businesses with overseas operations and supply chains, it added.

Some of these impacts are already being felt in the United States, the report said, and recent extreme weather and climate-related events can now be attributed “with increasingly higher confidence to human-caused warming.”

Compiled by more than 300 scientists, the Fourth National Climate Assessment Volume II is a congressionally mandated report that spans more than 1,000 pages.

US President Donald Trump dismissed last year’s report, and just this week appeared to confuse weather with climate when he tweeted: “Brutal and Extended Cold Blast could shatter ALL RECORDS – Whatever happened to Global Warming?”

Trump also yanked the United States out of the landmark 2015 Paris climate accord, signed by more than 190 nations to limit carbon emissions.

AFP / Sophie RAMIS. Global warming predictions.

David Easterling, director of the technical support unit at the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information, said there had been “no external interference” in the report.

Scientists found “clear and compelling evidence that global average temperature is much higher and is rising more rapidly than anything modern civilization has experienced,” he told reporters.

“And this warming trend can only be explained by human activities, especially emissions of greenhouse gases into the atmosphere.”

– Cascading effects –

Reporters questioned the timing of this year’s release, which came on the Friday after Thanksgiving, a national holiday when many people are traveling and shopping.

A NOAA spokeswoman said the report was “out earlier than expected” and was released ahead of two major scientific meetings on climate change in the coming weeks.

Meanwhile, the report warned that even if major cuts are made to harmful greenhouse gases (GHGs) like carbon dioxide and methane, the damage will linger for years.

“Because several GHGs, in particular carbon dioxide, reside in the atmosphere for decades or longer, many climate-influenced effects are projected to continue changing through 2050, even if GHG emissions were to stop immediately,” said the report.

AFP/File / Alex EDELMAN. The effects of climate change, such as the flooding seen in North Carolina during Hurricane Florence in September 2018, will get worse unless more drastic action is taken to cut carbon emissions, a major US government report warned.

Sea levels are continuing to rise, and extreme events like heavy rain and floods continue to increase worldwide, which will “cascade across economic sectors,” Easterling said, warning of “substantial net damage to the US economy.”

The report said it was “very likely that some physical and ecological impacts will be irreversible for thousands of years, while others will be permanent.”

The publication is designed to inform policy makers but does not make any specific recommendations on actions to take.

“In light of the report’s findings, it’s critical that federal, state and local governments take aggressive action to protect US residents by both reigning in emissions and helping communities adapt to the climate impacts that are now inevitable,” said Brenda Ekwurzel, the director of climate science at the Union of Concerned Scientists and one of the study’s authors.

Rush Holt, chief executive officer of the American Association for the Advancement of Science, said the economic warning shows that “policymakers can no longer afford to dismiss or ignore the overwhelming scientific evidence of climate change.”

Featured Photo: AFP/File / Robyn Beck. Climate change is expected to cause growing losses to American infrastructure and property and impede the rate of economic growth, according to a major new study.

If polar ice continues to melt, forests are slashed and greenhouse gases rise to new highs — as they currently do each year — the Earth will pass a tipping point.

Crossing that threshold “guarantees a climate 4-5 Celsius (7-9 Fahrenheit) higher than pre-industrial times, and sea levels that are 10 to 60 meters (30-200 feet) higher than today,” cautioned scientists in the Proceedings of the National Academy of Sciences.

And that “could be only decades ahead,” they said.

– What is ‘Hothouse Earth’? –

“Hothouse Earth is likely to be uncontrollable and dangerous to many,” said the article by scientists at University of Copenhagen, Australian National University and the Potsdam Institute for Climate Impact Research in Germany.

Rivers would flood, storms would wreak havoc on coastal communities, and coral reefs would be eliminated — all by century’s end or even earlier.

Global average temperatures would exceed those of any interglacial period — meaning warmer eras that come in between Ice Ages — of the past 1.2 million years.

Melting polar ice caps would lead to dramatically higher sea levels, flooding coastal land that is home to hundreds of millions of people.

“Places on Earth will become uninhabitable if ‘Hothouse Earth’ becomes the reality,” said co-author Johan Rockstrom, executive director of the Stockholm Resilience Centre.

– Where is the tipping point? –

Researchers suggest the tipping point could come once the Earth warms to 3.6 Fahrenheit (2 Celsius) over pre-industrial times.

The planet has already warmed 1 C over pre-industrial times, and is heating up at a rate of 0.17 C per decade.

“A 2 C warming could activate important tipping elements, raising the temperature further to activate other tipping elements in a domino-like cascade that could take the Earth System to even higher temperatures,” said the report.

This cascade “may tip the entire Earth system into a new mode of operation,” said co-author Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research.

Experts also worry about phenomena like wildfires, which will spread as the planet gets hotter and drier and have the potential to accelerate carbon dioxide buildup and global warming.

– How they calculated this –

The “Perspective” article is based on previously published studies on tipping points for the Earth.

The scientists also examined conditions the Earth has seen in the distant past, such as the Pliocene period five million years ago, when CO2 was at 400 ppm like today.

During the Cretaceous period, the era of the dinosaurs some 100 million years ago, CO2 levels were even higher at 1,000 ppm, largely due to volcanic activity.

AFP / Simon MALFATTO. Climate ‘tipping points’: the earth’s ticking time bombs.

To state that 2 C [3.6 F] is a no-return threshold “is new,” said Martin Siegert, co-director of the Grantham Institute at Imperial College London, who was not involved in the study.

The study authors “collated previously published ideas and theories to present a narrative on how the threshold change would work,” he said.

“It’s rather selective, but not outlandish.”

– How to stop it –

People must immediately change their lifestyle to be better stewards of the Earth, the researchers said.

Fossil fuels must be replaced with low or zero emissions energy sources, and there should be more strategies for absorbing carbon emissions such as ending deforestation and planting trees to absorb carbon dioxide.

Soil management, better farming practices, land and coastal conservation and carbon capture technologies are also on the list of actions.

Yet even if humans stopped emitting greenhouse gases, the current warming trend could trigger other Earth system processes, called feedbacks, driving even more warming.

These include permafrost thaw, deforestation, loss of northern hemisphere snow cover, sea ice and polar ice sheets.

Researchers say it’s not certain that the Earth can remain stable.

“What we do not know yet is whether the climate system can be safely ‘parked’ near 2 C above preindustrial levels, as the Paris Agreement envisages,” said Schellnhuber.

Featured Photo: AFP/File / PATRICK HERTZOG. A dried corn field is pictured on August 6, 2018 in Mitschdorf, eastern France, as a heatwave sweeps across Europe.

The annual State of the Climate Report, compiled by more than 450 scientists from over 60 countries, describes worsening climate conditions worldwide in 2017, the same year that US President Donald Trump pulled out of the landmark Paris climate deal.

The United States is the world’s second leading polluter after China, but has rolled back environmental safeguards under Trump, who has declared climate change a “Chinese hoax” and exited the Paris deal signed by more than 190 nations as a path toward curbing harmful emissions.

The 300-page report issued by the American Meteorological Society and the National Oceanic and Atmospheric Administration (NOAA) mentioned the word “abnormal” a dozen times, referring to storms, droughts, scorching temperatures and record low ice cover in the Arctic.

Here are its key findings:

– Greenhouse gas surge –

Last year, the top three most dangerous greenhouse gases released into Earth’s atmosphere -— carbon dioxide, methane and nitrous oxide -— reached new record highs.

The annual global average carbon dioxide concentration at the Earth’s surface climbed to 405 parts per million, “the highest in the modern atmospheric measurement record and in ice core records dating back as far as 800,000 years,” said the report.

“The global growth rate of CO2 has nearly quadrupled since the early 1960s.”

– Heat records –

The record for hottest year in modern times was set in 2016, but 2017 was not far behind, with “much-warmer-than-average conditions” across most of the world, it said.

Annual record high temperatures were observed in Argentina, Bulgaria, Spain and Uruguay, while Mexico “broke its annual record for the fourth consecutive year.”

Smashing more heat records, temperatures reached 110.1 degrees Fahrenheit (43.4 Celsius) on January 27 at Puerto Madryn, Argentina, “the highest temperature ever recorded so far south anywhere in the world.”

The world’s highest temperature ever for May was observed on May 28 in Turbat, western Pakistan, with a high of 128.3 degrees Fahrenheit.

“The 10 warmest years on record have all occurred since 1998, with the four warmest years occurring since 2014,” said the report.

Last year marked either the second or third hottest since the mid 1800s, depending on which data is consulted.

In another alarming milestone, 2017 was also “the warmest non-El Nino year in the instrumental record,” referring to the absence of the occasional ocean warming trend that pushes temperatures higher than normal.

– Abnormal Arctic –

Unprecedented heat enveloped the Arctic, where land surface temperature was 2.9 degrees Fahrenheit (1.6 Celsius) above the 1981–2010 average.

Arctic temperatures were the second highest — after 2016 — since records began in 1900.

“Today’s abnormally warm Arctic air and sea surface temperatures have not been observed in the last 2,000 years,” it said.

And glaciers across the world shrank for the 38th year in a row.

“Cumulatively since 1980, this loss is equivalent to slicing 22 meters off the top of the average glacier,” said the report.

In the Antarctic, sea ice extent remained below average all year, with record lows observed during the first four months.

– Record sea level –

Global sea level reached record high in 2017 for the sixth consecutive year.

The world’s average sea level is now three inches (7.7 centimeters) higher than in 1993.

“I think of the oceans like a freight train,” oceanographer Gregory Johnson from NOAA’s Pacific Marine Environmental Laboratory told reporters.

“If we were to freeze greenhouse gases at the level they are today, the oceans would continue to warm and seas would continue to rise for centuries to millennia.”

– Extreme rain –

Precipitation in 2017 “was clearly above the long-term average,” said the report.

Warmer ocean temperatures has led to increasing moisture in the air, particularly in the last three years, causing more rain.

Climate change can also exacerbate extreme weather.

Some parts of the world suffered extended droughts, demonstrating that “extreme precipitation is not evenly distributed across the globe.”

– ‘Most destructive’ coral bleaching –

Ocean warming over the last few years has been blamed for widespread coral bleaching, as disease spreads in this precious habitat for fish and marine life.

“The most recent global coral bleaching lasted three full years, June 2014 to May 2017, and was the longest, most widespread and almost certainly most destructive such event on record,” said the report.

Featured Photo: European Geosciences Union/AFP/File / Mario HOPPMANN. A handout photo provided by the European Geosciences Union on September 13, 2016 shows an undated photo of a polar bear testing the strength of thin sea ice in the Arctic.

But experts warn that ignoring sea level rise won’t prevent a looming economic crisis caused by water-logged homes that will someday become unsafe, uninhabitable and too costly to insure.

A reality check may come sooner than many may think, according to a report out Monday by the Union of Concerned Scientists, which finds as many as 64,000 coastal residences worth $26 billion in Florida are at risk of chronic flooding in the next 30 years, the life of a typical mortgage.

Across the United States, 311,000 coastal homes with a collective market value of about $120 billion in today’s dollars are at risk of chronic flooding by 2045, it said.

By century’s end, if current trends continue, more than $1 trillion in commercial and private US property may be at risk, “with Florida’s coastal real estate among the most exposed,” said the report.

And it’s not because of the increased risk of hurricanes or storm surge.

Rather, the danger comes from flooding due to high tides — sometimes called sunny day floods, or nuisance flooding — when water pools into streets, sidewalks, storefronts and homes.

“This risk is relatively near-term, well before places go underwater completely, and even in the absence of storms,” said Rachel Cleetus, lead economist and policy director with the Climate and Energy program at the UCS.

Coastal real estate markets are not currently factoring in these risks, she told AFP.

“But market perceptions can shift and they can shift quickly in some places,” she added, describing a market correction as “inevitable.”

– ‘Slow-moving disaster’ –

AFP / Kerry SHERIDAN. Florida’s coastal real estate is among the most exposed to chronic flooding in the US due to sea level rise, a study says.

To make the risks clearer to people, UCS released a searchable online map that shows where the danger is greatest, available at www.ucsusa.org/underwater.

The online realty site Zillow provided data for the analysis but did not take part in the scientific research.

The projections use a high-end scenario for sea level rise because that is an “appropriately conservative projection to use” when estimating risk to homes, often people’s largest asset, Cleetus said.

Chronic inundation is defined in the report as flooding that happens at least 26 times a year.

By 2045, rising seas are expected to bring an extra 1.8 feet (55 centimeters) of water along Florida’s coast, according to the UCS report.

By 2100, Florida can expect an average of 6.4 extra feet of water — an awful lot given that the state’s average elevation above sea level is only about six feet, with many places three feet or below.

“This is a slow-moving disaster,” said Cleetus.

The low-lying Tampa Bay area, Miami and The Keys island chain face the most peril from sea level rise.

One worry is that insurance premiums will increase so much that coastal homes become unaffordable for those with fixed or lower incomes.

Local governments may decide to cut power and water to flooded neighborhoods.

Many will risk losing their largest financial asset -– their homes — and municipalities will forfeit huge amounts of revenue from property taxes.

In Florida alone, the “homes at risk by 2100 currently contribute roughly $5 billion collectively in annual property tax revenue,” said the report.

– ‘If it rains…’ –

AFP/File / MARK RALSTON. Hurricane Harvey in August, 2017, dropped 51 inches of rain over Texas in 24 hours and damaged these boats in a multi-level storage facility.

The problem of outdated flood maps long predates US President Donald Trump, who has called global warming a hoax perpetrated by the Chinese, quit the Paris climate accords and rolled back environmental protections since taking office.

According to Desiree Companion, a certified floodplain manager employed by Sarasota County, the US government-issued flood maps that people consult when building or buying a home are decades old in many places.

During a free seminar at a local library this month, she said residents often tell her they don’t need flood insurance because they aren’t in a high-risk zone.

“If it rains where you are, you’d best be getting it,” she told the seven people gathered in a library meeting room, where most of the 50 seats were empty.

Federal flood maps are based on risk of a “100-year-event,” defined as 10 inches (25 centimeters) of rain falling in 24 hours, she explained.

Last year’s Hurricane Harvey dropped 51 inches over Texas in that amount of time.

“Everybody is in a flood zone,” she said.

– Who is to blame? –

Inaccurate flood risk information is just one of many factors fueling the crisis, said Jeffrey Huber, an assistant professor in the school of architecture at Florida Atlantic University.

“Nowhere is a realtor required to actually tell someone that the property they are purchasing is vulnerable to sea level rise,” he told AFP.

“Who is telling them that their property is vulnerable if not a realtor? If not an architect?”

Most developers know, and so do most municipalities, he added.

“The general audience isn’t necessarily educated enough to know.”

Solutions may be complex, but making significant cuts to greenhouse gas emissions would help, said report co-author Astrid Caldas, a senior scientist at UCS.

As much as 85 percent of the property at risk might be saved if the Paris Agreement goals are met, limiting warming to a maximum of 3.6 F (2 C) this century, she said.

“The longer we wait to drastically reduce emissions, the less likely it is that we will achieve this outcome.”

Featured Photo: AFP / Kerry SHERIDAN. A low-lying home near sea level in the Indian Beach neighborhood of Sarasota, Florida, a state where tens of thousands of coastal residences are at risk of chronic flooding, a study says.