The world could hit a tipping point that causes warming to spiral out of control — a scenario scientists call ‘Hothouse Earth’

Business Insider

• Humans have changed the world’s climate systems  by emitting carbon dioxide and other greenhouse gases.

• According to a new paper, humans could warm the world so much that we’d cause the planet’s natural climate systems to trigger further warming — a scenario called “Hothouse Earth.”

• In that world, the average temperature could rise 4 or 5 degrees Celsius more than it already has, leading to extreme heat and up to 200 feet of sea-level rise .

How Much Sea Level Rise Is Actually Locked in?

Forbes

One frequently sees articles claiming a certain amount of global warming or sea level rise is inevitable based on the amount of CO₂ already in the atmosphere. Locked-in warming is commonly estimated to be 1.5 degrees C (2.7° F) above preindustrial levels, about a one-half degree above the current temperature. This is the aspirational target of the 2015 Paris Agreement of the United Nations Framework Convention on Climate Change.

Although there may be some rhetorical benefit in this number, it understates the actual amount of committed warming and sea level rise predicted by mainstream climate change theory. The IPCC says, “Stopping emissions today is a scenario that is not plausible.” Therefore, we will inevitably have higher CO₂ concentration than the present, greater warming and more sea level rise.

Under the lowest of the IPCC’s four scenarios, RCP2.6, peak temperature rise of 2 degrees C will be reached before 2100, and sea level rise will be less than about a half meter. However, due to lag effects in ocean warming and ice melt, sea level will continue to rise for centuries. Rise can theoretically be reduced by negative carbon emissions or geoengineering.

Study: As Sea Levels Rise, Home Values Sink

Forbes

According to a peer-reviewed study of more than 5.5 million real estate transactions in Florida, South Carolina, North Carolina, Virginia and Georgia, sea level rise flooding has caused a total home value loss of $7.4 billion since 2005. Scientists from the non-profit First Street Foundation found that depreciation has already taken place in these areas from frequent tidal flooding.

“Within the five states analyzed, South Florida, the Charleston area of South Carolina and Norfolk, Virginia are experiencing some of the worst physical effects and market impact due to sea level rise,” says Steven McAlpine, head of data science at First Street Foundation.

The study used historical property sales data from 2005 to 2017. “Our research both confirmed that property lot flooding does impact homes, and additionally found that neighborhood flooding—which takes the proportion of nearby roads that flood into account—also contributes to slower appreciation of property value,” says Jeremy Porter, statistical consultant at First Street Foundation and professor at Columbia University.

Buried Internet infrastructure at risk as sea levels rise

Science Daily

Thousands of miles of buried fiber optic cable in densely populated coastal regions of the United States may soon be inundated by rising seas, according to a new study by researchers at the University of Wisconsin-Madison and the University of Oregon.

The study, presented July 16, 2018 at a meeting of internet network researchers, portrays critical communications infrastructure that could be submerged by rising seas in as soon as 15 years, according to the study’s senior author, Paul Barford, a UW-Madison professor of computer science.

“Most of the damage that’s going to be done in the next 100 years will be done sooner than later,” says Barford, an authority on the “physical internet” — the buried fiber optic cables, data centers, traffic exchanges and termination points that are the nerve centers, arteries and hubs of the vast global information network. “That surprised us. The expectation was that we’d have 50 years to plan for it. We don’t have 50 years.”

The study, conducted with Barford’s former student Ramakrishnan Durairajan, now of the University of Oregon, and Carol Barford, who directs UW-Madison’s Center for Sustainability and the Global Environment, is the first assessment of risk of climate change to the internet. It suggests that by the year 2033 more than 4,000 miles of buried fiber optic conduit will be underwater and more than 1,100 traffic hubs will be surrounded by water. The most susceptible U.S. cities, according to the report, are New York, Miami and Seattle, but the effects would not be confined to those areas and would ripple across the internet, says Barford, potentially disrupting global communications.