What is the worst single consequence of global warming?

Great Debates
101

No, and for details I refer you to the IPCC Climate Change 2014 Working Group 2 assessment, Impacts, Adaptation, and Vulnerability. At the highest level of generality, the following is from the Summary for Policymakers. It should be understood that each of these little bullet points represents a huge global issue which spans many geographic areas and many resource sectors. For instance, the enormous problem of sea level rise is just part of item (i); ocean acidification and many other problems of ecosystem destruction are just part of item (vii):
The key risks that follow, all of which are identified with high confidence, span sectors and regions. Each of these key risks contributes to one or more RFCs [formalized Reasons for Concern]:

i) Risk of death, injury, ill-health, or disrupted livelihoods in low-lying coastal zones and small island developing states and other small islands, due to storm surges, coastal flooding, and sea level rise.37 [RFC 1-5]

ii) Risk of severe ill-health and disrupted livelihoods for large urban populations due to inland flooding in some regions.38 [RFC 2 and 3]

iii) Systemic risks due to extreme weather events leading to breakdown of infrastructure networks and critical services such as electricity, water supply, and health and emergency services.39 [RFC 2-4]

iv) Risk of mortality and morbidity during periods of extreme heat, particularly for vulnerable urban populations and those working outdoors in urban or rural areas.40 [RFC 2 and 3]

v) Risk of food insecurity and the breakdown of food systems linked to warming, drought, flooding, and precipitation variability and extremes, particularly for poorer populations in urban and rural settings.41 [RFC 2-4]

vi) Risk of loss of rural livelihoods and income due to insufficient access to drinking and irrigation water and reduced agricultural productivity, particularly for farmers and pastoralists with minimal capital in semi-arid regions.42 [RFC 2 and 3]

vii) Risk of loss of marine and coastal ecosystems, biodiversity, and the ecosystem goods, functions, and services they provide for coastal livelihoods, especially for fishing communities in the tropics and the Arctic.43 [RFC 1, 2, and 4]

viii) Risk of loss of terrestrial and inland water ecosystems, biodiversity, and the ecosystem goods, functions, and services they provide for livelihoods.44 [RFC 1, 3, and 4]

Many key risks constitute particular challenges for the least developed countries and vulnerable communities, given their limited ability to cope.

102

Did you read the thread? Although much of the recent discussion has been on extreme weather most of the early replies were about ocean acidification and loss of arable land. There was a general consensus that ocean acidification is likely the most dire.

103

In the interest of accuracy, it was mentioned a few times but I don’t think anyone but you considered it “the most dire”. It’s unquestionably a big problem but climate change is also causing loss of biodiversity through lots of other ecosystem stresses, and even that in its totality is just one of a myriad of other problems. Indeed Anthony Barnosky and others have been proposing the idea that we are approaching a global ecosystem tipping point, a concept analogous to, but different from, a physical climate system tipping point.

However I would altogether reject the notion that there is any clear “worst single consequence” of climate change, but would rather point to items like those listed in #101 for a balanced perspective. Otherwise it’s like your house being on fire and asking someone to identify “the worst single thing” about it.

104

A related point:

“The Uninhabitable Earth”

105

I’m glad this thread got bumped! Re-reading it, I see one problem with climate scientists is that they talk like, well, scientists. “With medium certainty … if confirmed by further experiments … most likely … depending on …” It’s natural for many people to respond more positively to right-wing diction: “Hain’t no doubt whatsoever, you can bet your bloomin’ nuts … it’s just as certain as that the Good Lord tore down the walls of Jericho.”

[QUOTE=Czarcasm]
I did contribute already, but I have a question for you: What do you think is the worst single consequence of global warming?
[/QUOTE]

The NYMag.com article “The Uninhabitable Earth” is alarming. I hope our climate experts will put its conclusions in perspective. Don’t be afraid to use reassuring words like “if” or “uncertain” ! :cool:

106

A few stories I just saw recently:

The average global temperature is likely to increase well above the Paris accord target maximum of 2°C and will likely exceed 3°C by the end of this century.

Last June saw extreme weather and record-breaking temperatures across much of the western US.

Parts of South Asia could be too hot to live in by end of century.

Rising sea levels are causing an incursion of sea water along North American coastlines, killing trees and creating “ghost forests”.

107

If I could direct everyone’s attention to the graph in this article showing the high and low temperatures for Sacramento, CA … note that 109ºF is as normal as normal can be for that location … but look at the lows, specifically that 76ºF reading, THAT is exceptional … here in Western Oregon, the sheer number of overnight lows in the low 60’s is way above normal … almost to the point for putting away our jackets for the summer …

108

What are you talking about? The all time high temperature at a location is not normal as normal can be. I’m trying to figure out what you might have meant to say, because it doesn’t seem like the words you posted could possibly be it.

109

I honestly think on a 100 year time table we will come up with ways to mitigate the warming part of global climate change (of course, we will be dealing with all the issues folks have brought up with more intensive storms, drought and the like in the mean time), but ISTM that the acidification of the oceans is something we aren’t going to be able to easily deal with, especially coupled with the over fishing problem.

110

You need to read the article more closely … the 118ºF high temperature in Phoenix was the all time high for that particular calendar date (July 7th, 2017) … the all time highest temperature for Phoenix is 122ºF (June 26th, 1990) … there are 8 dates in July (over a quarter) where the highest temps have reached or exceeded 118ºF …

Your mistake is thinking “extreme” has the meaning of extraordinary in this context … nothing could be further from the truth … the dynamic conditions that brings these super high temperatures is normal, common and a fact of life when living in Phoenix, AZ … the only thing that’s extraordinary is the number of people affected by this heat wave … the record high for July 16th is also 118ºF set in 1925, when the population of Phoenix was under 50,000, today the population is over 1.6 million …

Also, keep in mind we’re in a period of global warming at least since 1880 … that fact directly implies that record high temperatures will be increasing slightly as time moves forward …

All weather data from NWS -> Climate Data -> Calendar day summaries … my browser gives me preset options for daily record high temperatures …

111

Of course one should notice that you dot deal with why it is the reason why it is warming.

As the source you rely on (NOAA) tells it:

One factor that you ignore when trying to still claim that this is not extraordinary:

One death was a sports woman that was very careful on doing her work on early mornings or just before sunrise. What changed was that there is less cooling nowadays at night time, a cooling that allows for a lot of critters and humans to function. There is really no other better explanation for that warming increase at night but the increase of CO2 and other global warming gases in the atmosphere.

https://www.cabrillo.edu/~rnolthenius/climate/KeyEvidence/Evidence.html

112

False. Almost all the anthropogenic warming that has occurred since industrialization has been happening since about the mid-20th century. And record high temperatures will not be “increasing slightly”, they will be accelerating (along with other forms of related extreme weather). That was the point of my first link; by the end of this century, the average global temperature will likely have increased three times as much as it has since the beginning of industrialization, due to increasing accumulations of long-lived greenhouse gases and the increasing magnitude of associated climate feedbacks.

I have no idea what that post, overall, is supposed to be saying, except maybe “extremes are the new normal”. Which is true but not exactly reassuring. The same picture is painted by the overall trends:
Two key climate change indicators – global surface temperatures and Arctic sea ice extent – have broken numerous records through the first half of 2016, according to NASA analyses of ground-based observations and satellite data.

Each of the first six months of 2016 set a record as the warmest respective month globally in the modern temperature record, which dates to 1880, according to scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York. The six-month period from January to June was also the planet’s warmest half-year on record, with an average temperature 1.3 degrees Celsius (2.4 degrees Fahrenheit) warmer than the late nineteenth century.

Five of the first six months of 2016 also set records for the smallest respective monthly Arctic sea ice extent since consistent satellite records began in 1979, according to analyses developed by scientists at NASA’s Goddard Space Flight Center, in Greenbelt, Maryland. The one exception, March, recorded the second smallest extent for that month.

While these two key climate indicators have broken records in 2016, NASA scientists said it is more significant that global temperature and Arctic sea ice are continuing their decades-long trends of change. Both trends are ultimately driven by rising concentrations of heat-trapping carbon dioxide and other greenhouse gases in the atmosphere.

113

This will get you a second, “What are you talking about?”

First you posted that an all time record high in Sacramento was as normal as normal could be. This didn’t make any sense so I asked what you were talking about and you responded with some unsolicited information about Phoenix, AZ.

If you don’t want to explain what you meant, I can’t make you. It’s just difficult to get at what you mean when what you mean seems to be a moving target.

In what way is the all time high in Sacramento, CA as normal as normal can be? What do you mean by that? What do you mean by normal? I can’t think of any standard usage where the most extreme example of a thing is considered normal.

114

We will probably have serious food production problems long before the oceans rise as much as 5 feet. The way so many programs and documentaries make a big deal of the effect of water rising 20 or 30 feet in New York and London is ridiculous.

Now there are articles about Southeast Asia becoming uninhabitable because of heat and humidity. That is 1.5 billion people.

So if that many people start moving from where they can’t live or feed themselves then we will have wars to stop them.

So all of the people pretending this is not an approaching crisis issue are ridiculous.

To a significant degree this comes down to our schools not teaching Real Science. Science is primarily A WAY OF THINKING. It is not just memorizing what scientists say are facts.

115

Not being a climatologist, I’m not in a position to predict exactly how it all goes down and how bad it would get by 2100, but I agree that generally, we’ll be noticing the effects long before then. At first, like now, they might just seem like unusually harsh weather: a 500 year flood, a 1,000 year drought, a year of 15 category 4 cyclonic storms hitting North America or Asia. But they’ll become increasingly severe and frequent. Long before South Florida becomes part of the Caribbean, you could insurance have companies saying: You know what? We ain’t insurin’ that - build it somewhere else.

116

New today: Study predicts worsening killer heat waves in Europe

117

I thought that melting ice in Greenland and Arctic was supposed to interfere with the Gulf Stream heat pump which warms Europe; and thus mitigate the effects of AGW there. Is this wrong?

Wishing Europeans no ill well, I hope that theory is wrong … since I never fully understood it. :stuck_out_tongue:

118

Might want to check your arithmetic, the temperature records from 1880 to 1950 are showing a warming period … so my claim is true in the case of general global warming … and I think man-kind contributed to this during the entire 1880 to present time frame, and probably much further into the past …

Yalp … with absolutely no technological advances and implementation … somehow I can’t see that happening in Europe … they seem motivated to stay at the forefront of these improvements …

119

It’s not wrong, just one hypothesized effect which might mitigate warming in some parts of Europe, but not to any great extent and only if it happens at all. Circulation changes are notoriously difficult to predict, but projections are that even if the AMOC drastically slows, Europe will continue to get hotter, albeit at a slightly slower rate. That’s because the majority of its climate impacts are from atmospheric heat transport, and from heat exchanges between ocean and atmosphere, rather than from oceanic heat transport. And warming at a slower rate may not mean much if overall global warming accelerates this century as much as expected.

120

Oreally? :wink: