Risk of extreme weather events higher if Paris Agreement goals aren't met

February 14, 2018, Stanford University
Noah Diffenbaugh, professor of Earth system science at Stanford University. Credit: L.A. Cicero

The individual commitments made by parties of the United Nations Paris Agreement are not enough to fulfill the agreement's overall goal of limiting global temperature rise to less than 2 degrees Celsius above pre-industrial levels. The difference between the U.N. goal and the actual country commitments is a mere 1 C, which may seem negligible. But a study from Stanford University, published Feb. 14 in Science Advances, finds that even that 1-degree difference could increase the likelihood of extreme weather.

In this study, Noah Diffenbaugh, the Kara J Foundation Professor of Earth System Science at Stanford's School of Earth, Energy & Environmental Sciences, and fellow researchers from Columbia University and Dartmouth College expanded on previous work analyzing historical climate data, which demonstrated how greenhouse gas emissions have increased the probability of recording-breaking hot, wet and dry events in the present climate. Now, the group analyzed similar models to estimate the probability of events in the future under two scenarios of the Paris Agreement: increases of 1.5 to 2 degrees if countries live up to their aspirations, or 2 to 3 degrees if they meet the commitments that they have made.

"The really big increases in record-setting event probability are reduced if the world achieves the aspirational targets rather than the actual commitments," said Diffenbaugh, who is also the Kimmelman Family Senior Fellow in the Stanford Woods Institute for the Environment. "At the same time, even if those aspirational targets are reached, we still will be living in a climate that has substantially greater probability of unprecedented events than the one we're in now."

Extreme events now and in the future

The new study is the latest application of an extreme event framework that Diffenbaugh and other researchers at Stanford have been developing for years. They have applied this framework to individual events, such as the 2012-2017 California drought and the catastrophic flooding in northern India in June 2013. In their 2017 paper on severe events, they found that global warming from human emissions of greenhouse gases has increased the odds of the hottest events across more than 80 percent of the globe for which reliable observations were available, while also increasing the likelihood of both wet and dry extremes.

The framework relies on a combination of historical climate observations and that are able to simulate the global circulation of the atmosphere and ocean. The group uses output from these models run under two conditions: one that includes only natural climate influences, like sunspot or volcano activity, and another that also includes human influences like rising carbon dioxide concentrations. The researchers compare the simulations to historical extreme event data to test whether the condition with natural or human influences best represents reality.

For the new study, the researchers expanded the number of climate models from their previous paper that had investigated the 1 degree of global warming that has already occurred, strengthening their earlier conclusions. Then, they used their findings to predict the probabilities of severe events in the two Paris Agreement scenarios.

Maps showing the risk of experiencing record-breaking warm nights in three global temperature scenarios. The present day scenario shows the increase in this risk versus the pre-industrial climate. Both the aspirational map and country commitment map show the increase in this risk compared to present day. Credit: Kurt Hickman

Although the researchers knew that increases in temperature would very likely lead to increases in severe events, the stark difference in the outcomes of the two scenarios surprised them.

The researchers found that emissions consistent with the commitments countries have made are likely to result in a more than fivefold increase in probability of record-breaking warm nights over approximately 50 percent of Europe, and more than 25 percent of East Asia. This 2 to 3 degrees of global warming would also likely result in a greater than threefold increase in record-breaking wet days over more than 35 percent of North America, Europe and East Asia. The authors found that this level of warming is also likely to lead to increases in hot days, along with milder cold nights and shorter freezes.

Meeting the Paris Agreement's goal of keeping the global-scale warming to less than 2 degrees is likely to reduce the area of the globe that experiences greater than threefold increases in the probability of record-setting events. However, even at this reduced level of global warming, the world is still likely to see increases in record-setting events compared to the present.

An opportunity to get ahead

When people build a dam, plan the management of a river or build on a floodplain, it is common practice to base decisions on past historical data. This study provides more evidence that these historical probabilities no longer apply in many parts of the world. The new analysis helps clarify what the climate is likely to look like in the future and could help decision makers plan accordingly.

"Damages from extreme weather and climate events have been increasing, and 2017 was the costliest year on record," Diffenbaugh said. "These rising costs are one of many signs that we are not prepared for today's climate, let alone for another degree of ."

"But the good news is that we don't have to wait and play catch-up," Diffenbaugh added. "Instead, we can use this kind of research to make decisions that both build resilience now and help us be prepared for the that we will face in the future."

Explore further: Avoiding increases of extreme heat events over East Asia by 0.5 degrees C

More information: N.S. Diffenbaugh at Stanford University in Stanford, CA el al., "Unprecedented climate events: Historical changes, aspirational targets, and national commitments," Science Advances (2018). advances.sciencemag.org/content/4/2/eaao3354

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26 comments

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cantdrive85
1 / 5 (5) Feb 14, 2018
Meanwhile, when reality is actually considered, we will absolutely see more extreme weather due to Earth's weakening magnetic field, regardless of that political agreement.
Benni
1 / 5 (10) Feb 14, 2018
Isn't this just sweet logic. As long as world leaders are sitting around a table in France talking about implementing an AGW agenda, then planet Earth holds off on warming itself, but the minute planet Earth finds out that the Paris Accords thing is being delayed for implementation then planet Earth tentacle like sensors pick up on the buzz & ramps up global warming.

Those planet Earth tentacles need to figure out how to stretch to the Sun before the predicted 2050 Sun Dimming event occurs.

aksdad
1.5 / 5 (8) Feb 14, 2018
Yet strangely, the IPCC AR5 (2013) report says this about wet and dry extremes (Chapter 2):

Regional trends in precipitation extremes since the middle of the 20th century are varied (p.213)

low confidence regarding the sign of trend in the magnitude and/or frequency of floods on a global scale (p.214)

low confidence in a global-scale observed trend in drought or dryness (lack of rainfall) since the middle of the 20th century (p.215)

As for temperature "extremes", lets not forget that according to the global temperature records from 1850 to the present, the global average temperature has increased by about 1 to 1.2° C.

http://berkeleyea...arge.png

That's roughly the temperature difference you feel when climbing about 100 meters (330 feet) higher up a hill or mountain. Not much at all and certainly not extreme.

See IPCC report at https://www.ipcc....ar5/wg1/
leetennant
4.6 / 5 (10) Feb 14, 2018
The difference between the U.N. goal and the actual country commitments is a mere 1 C, which may seem negligible...

Sure, it's the difference between extreme weather events and total societal collapse. It only "seems negligible" because people don't understand climate science.


As for temperature "extremes", lets not forget that according to the global temperature records from 1850 to the present, the global average temperature has increased by about 1 to 1.2° C. That's roughly the temperature difference you feel when climbing about 100 meters (330 feet) higher up a hill or mountain. Not much at all and certainly not extreme


As demonstrated by aksdad. Thanks!

The words "global" and "average" continue to be complex scientific terms past the grasp of mere mortals apparently
sirdumpalot
not rated yet Feb 15, 2018
I always loved sim-city when you turned on the natural disasters!
humy
3 / 5 (2) Feb 15, 2018
Meanwhile, when reality is actually considered, we will absolutely see more extreme weather due to Earth's weakening magnetic field, regardless of that political agreement.

That's a joke, right?
humy
1 / 5 (1) Feb 15, 2018
Meanwhile, when reality is actually considered, we will absolutely see more extreme weather due to Earth's weakening magnetic field, regardless of that political agreement.

That's a joke, right?
humy
5 / 5 (3) Feb 15, 2018

There is no evidence that weakening magnetic field will significantly increase extreme weather events.
humy
5 / 5 (3) Feb 15, 2018
Sorry, don't know what went wrong there but didn't deliberately post that 9 times! I only meant to post that ONCE.
cantdrive85
1 / 5 (2) Feb 15, 2018
There is no evidence that weakening magnetic field will significantly increase extreme weather events.

How exactly do you figure? Weaker solar and Earth magnetic fields will allow more cosmic rays to bombard Earth's atmosphere, hence more extreme weather among other effects.
Turgent
1.7 / 5 (6) Feb 15, 2018
How I would like to see one paper addressing GW at the fundamental level of CO2 radiative absorption. Increased CO2 → Increased atmospheric energy → More destructive weather.

Don't you love such out of context statements like "Damages from extreme weather and climate events have been increasing, and 2017 was the costliest year on record," Diffenbaugh said. "These rising costs are one of many signs that we are not prepared for today's climate, let alone for another degree of global warming." What malarkey we have never prepared for the 1 in a 100 year or 500 year extreme. More people more destruction, dah. We've had a 12 year hiatus of hurricanes, built evermore communities in places, like the Gulf Coast, where they shouldn't be, and as the case of Puerto Rico ignore building codes. More people more damage. Then the odds catch up with us and CO2 is the culprit.

cont.
Turgent
1.7 / 5 (6) Feb 15, 2018
I tried to find a detailed description and mathematical layout of the simulation (assumed to be CLIMDEX) and stopped looking after 20 minutes.

One thing the atmosphere has not done is change temperatures at the altitudes predicted.

If anyone can identify a source where fundamental properties and/or coefficients of CO2 absorption can be found please provide direction. Also should you know of any place where a visible model in mathematical form may be found please provide such.
PTTG
5 / 5 (3) Feb 15, 2018
@Benni

I don't know if you're a moron or you think everyone else is a moron.
rodkeh
2 / 5 (4) Feb 15, 2018
The only real risk is from the ignorance and stupidity of people like this professor Noah Diffenbaugh!
guptm
1.7 / 5 (6) Feb 15, 2018
Science that threatens people is fake!
leetennant
5 / 5 (5) Feb 15, 2018
Science that threatens people is fake!


Just out of curiosity, what does this inane blanket statement cover? Our scientific knowledge of poisons? Our knowledge of necessary nutrient intake? Our knowledge of gravity?

Are you saying that gravity is just a scam to stop you exercising your God-given right to jump off buildings? #jumpagainstgravity
chuck_in_st_paul
1 / 5 (7) Feb 15, 2018
ROFLMAO

one more attempt to scare the herd into self destructive and costly "fixes" that won't, and aren't needed.
humy
5 / 5 (5) Feb 16, 2018

Weaker solar and Earth magnetic fields will allow more cosmic rays to bombard Earth's atmosphere, hence more extreme weather among other effects.

cantdrive85

How does
"more cosmic rays to bombard Earth's atmosphere"
imply
" more extreme weather"
?
And where is your evidence for such a causal link?
You do know it isn't cosmic rays that seeds hurricanes and tornadoes on Earth, right?
cantdrive85
1 / 5 (4) Feb 16, 2018
You do know it isn't cosmic rays that seeds hurricanes and tornadoes on Earth, right?

You know this with absolute certainty? You must be the "Superfantastic Science Guy".

https://principia...xpected/
humy
5 / 5 (4) Feb 17, 2018
You do know it isn't cosmic rays that seeds hurricanes and tornadoes on Earth, right?

You know this with absolute certainty?


I know this with sufficient certainty to call it fact just like I know with sufficient certainty that the Earth isn't flat to call it a fact that the Earth is round. It is because of this called "science".
Your link doesn't claim it is cosmic rays that seed hurricanes and tornadoes on Earth thus is irrelevant.

lets see what the science says shall we?
http://www.weathe...anes.htm
cantdrive85
1 / 5 (3) Feb 17, 2018
And that is relevant, because?
First, tornadoes and hurricanes are not the only extreme weather events under discussion, that is why it is relevant.
Second, your link to a "science" website for children is swell. But what causes low pressure? It is the electrodynamic properties of the matter/atmosphere which creates the high/low pressure zones. Ultimately these processes are driven by electric potential which determines the pressure systems. As the Earth's magnetosphere weakens even small fluctuations in the Sun's activity/cosmic rays can have greater impacts.
Captain Stumpy
3 / 5 (4) Feb 17, 2018
@idiot eu cult acolyte cd
your link to a "science" website for children is swell
he was trying to make sure you could understand it as you've only demonstrated a 5th grade comprehension of science and reading
It is the electrodynamic properties
... Ultimately these processes are driven by electric potential
no

and I can prove that easily:
- if you simply overlay all the storms and extreme weather events with the exposed power grid and transfer stations, you will not find a correlation supporting your belief

Also note: there are less "electrodynamic properties" in the ocean than on first world national lands, so why do hurricanes start in oceans?

these land areas in any developed nation, per your claim, should seed extremely violent weather

they do not

moreover: influence isn't the same thing as seeding, so your idiocy is invalidated simply because you can't comprehend basic English

humy
5 / 5 (3) Feb 19, 2018
But what causes low pressure?

cantdrive85

NOT cosmic rays for sure. Your baseless claims are idiotic.
Are you a climate scientist? If not, how can you know about it better than them? THEY don't say cosmic rays causes low pressure in the weather systems.
humy
5 / 5 (2) Feb 19, 2018

Are you a climate scientist?


I think it might be better for me to have asked instead;

Are you a meteorologist or an atmospheric physicists?

although I guess a climate scientist would do.
CubicAdjunct747
1 / 5 (3) Feb 19, 2018
the amount of money spent on paris could already have been used for co2 sequestration/and or energy usage and start putting a dent in the amount of co2. Misguided funds once again. stupid humans, you lack cohesion, which will be your undoing. most of you will be alive when your planet dies!
cantdrive85
1 / 5 (3) Feb 19, 2018
But what causes low pressure?

NOT cosmic rays for sure. Your baseless claims are idiotic.

I never said cosmic rays cause low pressure, you are obviously an idiot if you think I said such a thing. What I said;
"But what causes low pressure? It is the electrodynamic properties of the matter/atmosphere which creates the high/low pressure zones." cantdrive85
The primary underlying cause of all weather is due to the electrodynamic properties of the matter/atmosphere, as such it is greatly affected by electrodynamics.
Are you a climate scientist?

Appeal to authority much? The problem with climate science is that it must rely on assumptions, beliefs, and theories from other disciplines to develop their own theory/models. Sadly, the climate scientists rely upon the plasma ignoramuses (astrophysicists) to tell them how the Sun-Earth energy transfer occurs. Needless to say, they are so completely wrong it in turn causes the climate scientists to be mislead.

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