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A harder rain’s a-gonna fall in the US

Ever-heavier downpours threaten mainland America with harder rain as a consequence of global warming. US cities need to be ready.

LONDON, 11 December, 2017 – For the US, harder rain is on the way: America’s summer thunderstorms are about to get stormier. Later this century, the notorious mesoscale convective storms of middle America will not just darken US skies: they will dump as much as 80% more water  on the farms, highways and cities of the 48 contiguous states.

Mesoscale thunderstorms cover an area of around 100 kilometres: these have been on the increase, both in frequency and intensity, in the last 35 years and new research suggests that, as the world warms, their frequency could triple.

“The combination of more intense rainfall and the spreading of heavy rainfall over larger areas means that we will face a higher flood risk than previously predicted,” said Andreas Prein, of the National Centre for Atmospheric Research in the US, who led the study.

“If a whole catchment area gets hammered by high rain rates, that creates a much more serious situation than a thunderstorm dropping intense rain over parts of the catchment. This implies that the flood guidelines which are used in planning and building infrastructure are probably too conservative.”

Thunderstorms already cost the US around $20bn a year in flash floods, landslides, debris flows, high winds and hail. Dr Prein and his colleagues report in Nature Climate Change that what they call “observed extreme daily precipitation” increased in all parts of the US from 1958 to 2012: that is because rising temperatures mean more evaporation, and at the same time a greater atmospheric capacity for moisture.

“The floods of the future are likely to be much greater than what our current infrastructure is designed for”

US President Donald Trump has made it clear that he doesn’t believe in global warming and has promised to withdraw the US from the global climate pact agreed by 197 nations in Paris in 2015.

But research, much of it from US government agencies, suggests that climate change is happening anyway, and that US cities are at risk. The latest computer simulations suggest that the number of extreme summer storms in some parts of the US could have increased fivefold by the century’s end.

Even the eastern seaboard could be hit: intense storms over an area the size of New York City could drop 60% more rain than the heaviest now. And this could add up to six times the annual discharge of the Hudson River.

The finding should come as no great surprise. Climate scientists have repeatedly warned that climate change, driven by global warming as a consequence of the profligate combustion of fossil fuels that dump ever greater levels of greenhouse gases in the atmosphere, could bring ever greater extremes of heat and rain.

More Harveys

Recent research has predicted that the kind of rainfall delivered by Hurricane Harvey over Houston in Texas could become much more frequent, and Atlantic communities are more likely to be pounded by hurricanes and superstorms.

Other long-term studies have predicted that coastal flooding could create a new class of climate refugees, within America itself. The latest study is a reminder that civic authorities, and the administration itself, need to prepare.

“This is a warning signal that says the floods of the future are likely to be much greater than what our current infrastructure is designed for,” Dr Prein said.

“If you have a slow-moving storm system that aligns over a densely populated area, the result can be devastating, as could be seen in the impact of Hurricane Harvey on Houston.” – Climate News Network

The post A harder rain’s a-gonna fall in the US appeared first on Climate News Network.

Source: Climate News Network – A harder rain’s a-gonna fall in the US

Why you should join The EB Circle

Eco-Business has unveiled a new membership programme called The EB Circle for its growing community. Join us and be part of the global sustainable development story.
Source: Eco Business – Why you should join The EB Circle

San Francisco tightens regulations on delivery robots

A new ordinance will make it difficult for businesses to test delivery robots in real-life situations.

Source: Sustainable Cities Collective – San Francisco tightens regulations on delivery robots

Report: Feds will allocate more transportation funds to states that raise taxes to pay for infrastructure

Infrastructure plans have fallen by the wayside as the Trump administration has prioritized repeal of Obamacare, tax reform and other initiatives. 

 

Source: Sustainable Cities Collective – Report: Feds will allocate more transportation funds to states that raise taxes to pay for infrastructure

San Francisco rolls out citywide demand-based parking prices

The city is the first in the U.S. to implement this type of a program at all of its meters and garages.

Source: Sustainable Cities Collective – San Francisco rolls out citywide demand-based parking prices

Australia launches database for evaluating its largest cities

The system displays gathered information about 21 cities based on key productivity metrics.

Source: Sustainable Cities Collective – Australia launches database for evaluating its largest cities

New Hampshire becomes the first state to opt out of FirstNet

The state will use an alternative service provider to build and maintain is emergency communications network.

Source: Sustainable Cities Collective – New Hampshire becomes the first state to opt out of FirstNet

Lyft now offering self-driving rides in Boston

The vehicles are operated by nuTonomy, which touts this partnership as the "first-ever public pilot between a ride-sharing company and an autonomous vehicle company" in the U.S.

Source: Sustainable Cities Collective – Lyft now offering self-driving rides in Boston

Hotter world than predicted may be here by 2100

A hotter world could be on the way, unless nations act. That’s because the gloomiest predictions may not have been gloomy enough.

 

LONDON, 8 December, 2017 – Tomorrow may experience a hotter world than anyone had feared. Global warming, under the notorious “business-as-usual scenario” in which humans go on burning fossil fuels to power economic growth, could by 2100 be at least 15% warmer than the worst UN projections so far. And the spread of uncertainty in such gloomy forecasts has been narrowed as well.

Climate scientists had worked on the assumption that there was a 62% chance that the world would have warmed on average by more than 4°C if no action was taken to reduce greenhouse gas emissions.

But a new study has not only raised the stakes, it has narrowed the uncertainty. There is now a 93% chance that global warming will – once again, under the business-as-usual scenario – exceed 4°C by 2100.

And since, in Paris in 2015, the world’s nations met and agreed to keep overall global warming to “well below” 2°C,  even that figure represents “dangerous” global warming.  One degree higher would count as “catastrophic”. And a rise of beyond 5°C would deliver the world into an unknown and unpredictable period of change.

“If emissions follow a commonly-used business-as-usual scenario, there is a 93% chance that global warming will exceed 4°C by the end of this century”

Two US scientists report in the journal Nature that they went back to the climate models used as the basis for forecasts made by the UN’s Intergovernmental Panel on Climate Change and then matched the reasoning against observations.

In particular, they looked again at seasonal and monthly variability in climate and the latest thinking about energy use, and carbon dioxide emissions, and their impact on temperatures.

There has always been an argument about the long-term accuracy of climate models and what they can usefully predict about the real world by the century’s end. If anything, the new results suggest that tomorrow’s reality could be even worse.

“Our results suggest that it doesn’t make sense to dismiss the most-severe global warming projections based on the fact that climate models are imperfect in their simulation of the current climate,” said Patrick Brown, of the Carnegie Institution at Stanford University in California.

Deeper cuts

“On the contrary, we are showing that model shortcomings can be used to dismiss the least severe predictions.”

And, the authors warn: “Our results suggest that achieving any given global temperature stabilisation target will require steeper greenhouse gas emissions reduction than previously calculated.”

Climate models are only as good as the climate data on which they are based, and one source of uncertainty has been the effect of warming on cloud formation: a warmer world means more evaporation, which could mean more warmth is trapped in the atmosphere – or it could mean more clouds, which reflect more solar radiation back into space.

For decades, researchers have tried to calculate with precision the links between ratios of greenhouse gases released from the combustion of coal, natural gas and oil, and shifts in average planetary temperature.

Simpler evidence

One of the Carnegie authors, Ken Caldeira of the Institution’s global ecology lab, has so far calculated the rate at which carbon dioxide sets about warming the atmosphere, and the capacity of greenhouse gases to go on warming the world for millennia.

The latest conclusions have been based on simpler evidence: the accuracy with which their forecast models can “predict” the recent past.

Professor Caldeira said: “It makes sense that the models that do the best job at simulating today’s observations might be the models with the most reliable predictions.

“Our study indicates that if emissions follow a commonly-used business-as-usual scenario, there is a 93% chance that global warming will exceed 4°C by the end of this century. Previous studies have put this likelihood at 62%.” –  Climate News Network

The post Hotter world than predicted may be here by 2100 appeared first on Climate News Network.

Source: Climate News Network – Hotter world than predicted may be here by 2100

London’s great smog prompts link with Delhi

The UK has cleaner air than in 1952 when the great smog of London descended on the capital – but not yet clean enough for thousands.
Source: Eco Business – London’s great smog prompts link with Delhi