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"Our goal though would be to decrease the forcings over time and bring the temperatures down to avoid losing too much of the Greenland and Antarctic ice sheets"
Imagine two scenarios, which stay within the 1.5C limit:(A) heats the Earth more than (B).
(A) Global surface temperature rises to the 1.5C limit immediately and remains there until 2100.
(B) Global surface temperature rises steadily to 1.5C just reaching 1.5C in 2100.
Both are Compliant with the Paris Agreement.
Sustained SLCP emissions result in stable forcing. Eventually, if maintained indefinitely,this results in no additional warming
Ocean warming dominates the increase in energy stored in the climate system, accountingIPCC AR5, WG1,Summaryfor Policymakers
for more than 90% of the energy accumulated between 1971 and 2010 (high confidence).
It is very likely that there is a substantial anthropogenic contribution to the global mean sea level rise since the 1970s. This is based on the high confidence in an anthropogenic influence on the two largest contributions to sea level rise, that is thermal expansion and glacier mass loss.IPCC AR5, WG1,Summaryfor Policymakers
Methane emissions & Small Island Developing States (SIDS)
SIDS asked for a limit on GMST of 1.5C to limit sea levels.
Methane is short-lived with a short-lived effect on GMST.
… Its effect on peak GMST is only significant near peak.
But, methane heating increases sea level for centuries.
The SIDS got the wrong target …
Methane emissions will help to drown them.
Scripps Oceanography geochemist Ralph Keeling said fossil fuel use would have to decline by about 10 percent around the world and would need to be sustained for a year to show up clearly in carbon dioxide levels.
History has shown that carbon dioxide levels typically resume their climb quickly as normal economic activity rebounds. If there is any benefit of the coronavirus event in terms of slowing the pace of climate change, it could be the changing of people’s travel and work habits in ways that lead to sustained reductions in fossil fuel use. Only those kinds of long-term systemic reductions will change the trajectory of carbon dioxide levels in the atmosphere, Keeling said.
Our societies have reorganised themselves around the reality of pervasive personal transport.
outright reductions in travel demand (e.g., as a result of integrated transport, land-use and urban planning), figure much less prominently.
We can have cars to drive or a planet to live in.
1. Am I correct in thinking that some of these feedbacks were not used in the models that calculated the “remaining carbon budgets” – as used in the IPCC AR5? [That’s the CMIP5 models]QuoteThat’s correct, the models used vary in what they include, and some feedbacks are absent as the understanding and modelling of these is not yet advanced enough to include. From those you raise, this applies to melting permafrost emissions, forest fires and wetlands decomposition.
In total, 6.735 megatonnes of carbon dioxide were released into the atmosphere by wildfires between 1 January and 30 November 2019. This value fits with the gradual declining trend in global total fire emissions since 2003, related to changing land management practices and use of fire in the tropics.
.Builders like angular sand of the kind found on riverbeds. Sand, sand everywhere, nor any grain to use, to paraphrase Coleridge. A textbook example is the Burj Khalifa in Dubai, the world’s tallest skyscraper. Despite being surrounded by sand, it was constructed with concrete incorporating the “right kind of sand” from Australia.
A representative remaining carbon budget ...
Different judgements can be made of what quantity is a reasonable
total GHG emissions budget for people living now. A personal judgement
will depend on things like:
1) What you think the consequences are
2) How Earth saving technology will develop
3) How much you care about the future
4) Whether mitigation is a lost cause.
Notes ...
(1) is often described in terms of global mean surface temperature but
this is just an imperfect proxy for horrid things happening
(2) depends on things like the confidence in things like BECCS
(3) is personal morality
(4) is how much you believe Guy McPherson.
Not precisely determined ...
Clearly a representative remaining carbon budget is not something
that can be precisely determined: It is a mixture of science, morality
and personal judgement.
Despite these difficulties, I believe that a quantified figure would be
very helpful for planning - even if the quantity was simply an average
of "expert" opinions.
I'm skeptical of the whole concept because I've lived in that carbon budget. It's unwelcome in society. Any hail mary ideas
https://www.aalto.fi/en/department-of-design/15-degrees-lifestyles
360 gigatonnes / 7.7 billion = 46.75 tonnes remain for each person on earth. At the global average of 5.25 tonnes per annum, that's a shade under 9 years before the world population would need be carbon neutral.
I wonder if talking about 1.5C target is actually counterproductive.
It's not really an estimate I've done myself, but I thought it was more like 100 tonnes. I mean, that's hard enough to achieve for the rest of my life (I'm 45), but 63 tonnes would be even more difficult, especially for children in the west that are still in the midst of their process of total consumer conditioning.
We each have a personal budget 64 tonnes CO2e left, and this development is for people emitting 15 tonnes CO2e/year. We must find a better way.
But do we now have? :
1.Cars - very, very, bad from the start.
2.Beef & lamb - very bad from the start.
3.Fossil fuel power - very bad but we worry about losing the initial cooling.
4.High buildings - bad but the embodied CO2 comes from "industry" so some initial cooling.
5.Planes - not so bad but we worry about losing the initial cooling.
6. Trees - where can they be planted to avoid the aerosol warming effects?
The principal implication of our present analysis probably relates to the Faustian bargain. Increased short-term masking of greenhouse gas warming by fossil fuel particulate and nitrogen pollution represents a 'doubling down' of the Faustian bargain, an increase in the stakes. The more we allow the Faustian debt to build, the more unmanageable the eventual consequences will be. Yet globally there are plans to build more than 1000 coal-fired power plants (Yang and Cui 2012) and plans to develop some of the dirtiest oil sources on the planet (EIA 2011). These plans should be vigorously resisted. We are already in a deep hole—it is time to stop digging.
For a while now, the scientific community has known that global warming is caused by human made emissions in the form of greenhouse gases and global cooling by air pollution in the form of aerosols.
However, new research published in Science by Hebrew University of Jerusalem Professor Daniel Rosenfeld shows that the degree to which aerosols cool the earth has been grossly underestimated, necessitating a recalculation of climate change models to more accurately predict the pace of global warming
According to Unger’s latest findings, the volatile organic compounds (VOCs) emitted by trees heat our climate. It’s controversial because it’s a new idea, modeled by Unger, and there are lots of ways to run a model.
"From the point of view of the general public, there's been a level of anxiety that people feel recently about their carbon footprint when they go to airports," Unger said. "We should be feeling that way when we turn on our car ignitions."
[Electric buses] are too expensive for municipalities to buy enough to serve all the populations and locations that need them.
Derwenthorpe was meant to be sustainable and have a low carbon footprint but it achieved a planet-destroying footprint of 14.52 tonnes CO2e per resident per year. This was worse than the average for York as a whole, which was still planet-destroying at 14.30 tonnes CO2e.
World average emissions of CO2e are now about 7 tonnes CO2e per person per year. This racks up a planet-threatening 100 tonnes of CO2e in fifty years – even if emissions steadily declined to zero during that time (OK, this is optimistic.). Emissions from Derwenthorpe and the rest of York are more than twice the world average.
I think Europe has a much bigger chance (though not big at all) of reducing the number of cars on the roads, than we in the US.
The father of the American shopping mall, the Austrian-born architect Victor Gruen, envisioned the mall as a sort of European-style town center for the American suburbs. He saw malls as climate-controlled Main Streets, with post offices, supermarkets and cafes, set amidst larger complexes with schools, parks, medical centers and residences. You’d hardly need to drive at all. Gruen found cars repulsive.
But only part of Gruen’s vision caught on: the climate-controlled gray box, famous for encouraging car culture rather than stopping it. In 1978, the elderly Gruen railed against what his idea had become.
“I would like to take this opportunity to disclaim paternity once and for all,” he said. “I refuse to pay alimony to those bastard developments. They destroyed our cities.”
Malls are dying in some places, yes, their too-expensive-to-remove corpses littering the landscape. But in other places malls are becoming “lifestyle centers” much like what Gruen envisioned. And some are going beyond that, turning into entirely different things: apartment complexes, churches, schools. Down the road, urban planners see even more uses: farms, performance venues, pop-up event spaces.
The estimates of the emissions from having an extra child used a method developed by Murtaugh and Schlax. This is the method:
–1– Assign half of a child’s emissions to each parent
–2– Add one quarter of the emissions of each grand-child
–3– Add one eighth of the emissions of each great-grand-child
–4– …and so on.
As the number of descendants increase the carbon emissions add up to a very large amount – even though for each descendant the share of their emissions is diminishing. Wynes & Nicholas considered carbon emissions in ‘developed’ nations (average lifetime 80 years), it is possible to see that their estimate of the carbon cost of having an extra child is about 4,668 tonnes CO2e – over 46 times the individual budget (100 tonnes CO2e) for avoiding “dangerous climate change”.
One flaw in this argument is the assumption made by Murtaugh and Schlax that future generations will have carbon emissions similar to the initial parents.
The reason is the sheer routine stupidity of the cases made for Population being a significant factor in resolving global warming.
Look how many years how many commenters have continued pushing the same routinely debunked arguments - while ignoring all of the cogent arguments for actual climate action - and you have something other than a serious widespread honest concern.
What you have is somebody's propaganda effort, predictably using shills, bots and anyone they can get to parrot the chosen memes.
From where I stand there is a fairly clear explanation of this, which is that public opinion is being programmed to see massive future famine casualties in developing countries as 'inevitable', and 'due to the coloureds overbreeding' and 'nothing the US should change course over', such as by taking emergency climate action by SSA geoengineering.
Population is a complete red herring in regards to 2°C budgets.
Even more so in regards to 1.5°C budgets, which are not physically possible any more--partly because we've been delayed by people lying about this and other red herrings.
A pity they didn't do a precis - say two pages of one-liners. It would be, I think, a very powerful document. I don't think I dare.
I really wish you would G..
"EIA has great data this morning:
1) 2017 carbon emissions down 0.9%;
2) 2017 emissions 14% below 2005 levels;
3) Total carbon emissions from gas higher than coal;
4) Petroleum top emitter, responsible for 46% of total emissions.”
https://mobile.twitter.com/johnrhanger/status/1037323456226967552
do you have numbers regarding the average carbon footprint of a motorist, and by EU countries (mainly UK, France, Germany, Spain, Italy)? and what is the car emission share within the overall carbon footprint of an average citizen?
the richest 10 per cent of households nationally consuming three times more carbon for household energy and travel than the poorest 10 per cent.
The whole point of this thread's argument is about Ned's claim that CH4 will be insignificant in future decades.
One of the authors, Dr Michelle Cain, explains in , that since methane has a lifetime of about 10 years it does not contribute much to long-term temperature rise and the goal of the Paris Agreement.
However, the temporary warming caused by methane will have gone somewhere: A higher surface temperature for a decade or so will cause some of the heat to be lost to space but some of the warming will have contributed to melting ice sheets and a much larger amount will have warmed the oceans, raising sea levels.
In Emission metrics and sea level rise, Sterner and Azar, discuss sea level rise caused by short-lived pollutants, such as methane. Their conclusions show that methane is many times worse than CO2 – for sea level rise even though it does not affect log-term surface temperatures greatly.
Perhaps the Small Island Developing States must agree with Myles Allen, who thinks methane emissions from current meat production is not much of a problem:Quote“We don’t actually need to give up eating meat to stabilise global temperatures,” says Professor Myles Allen who led the study (meat production is a major source of methane). “We just need to stop increasing our collective meat consumption.”
But the Small Island Developing States might worry about our meat consumption (especially beef and lamb) because it causes significant sea-level rise through enhanced methane emissions – although it doesn’t affect long term average global temperatures much.
I think it's rather axiomatic that the best way to prevent future forcing is to cut back on present forcings, preferably using the most efficient methods.
short term heating can cause the feedbacks discussed in Lowe & Bernie’s paper mentioned below
A teacher with no children goes on several big flights a year. She has a lifestyle far more sustainable than a family of 5, no matter how little they travel.
This was on the BBC front page this morning as well... briefly. At least awareness of these dire possibilities is starting to reach the mainstream, even if it's rapidly displaced by politicians choosing unfortunate wording.
Zeb Soanes:
The scientific community has reacted cautiously to a new study which warns that the world is at risk from dangerous levels of climate change the could make some areas of the planet uninhabitable. The paper by a team at the University of Stockholm predicts that as global warming gathers pace it will become impossible to control but while many other researchers acknowledge the threat posed they say the predictions in this latest report a very much a worst case scenario our science editor David Shukman has been weighing up the arguments.
David Shukman:
At a time of multiple heat waves from California to Britain to Japan an apocalyptic vision of an overheated future, what's called a hothouse Earth has caught the imagination. The scientists argue that natural features of the planet help to keep it cool. The oceans and the forests absorb much of the carbon dioxide released by cars, factories and power stations and without them the gas would into the atmosphere and raise temperatures further but it's suggested if there's damage to these natural buffers a series of dominoes would suddenly fall. The frozen soils in the arctic releasing methane, the melting of the ice sheets accellerating, weather patterns shifting and whole region becoming hostile to life. So how plausible is this?
Individually each of these processes is physically possible but taken together the idea of a cascade of impacts triggering runaway warming is more extreme than many other studies of climate change. It goes far beyond the carefully drafted assessments of the United Nations.
Privately some scientists not involved in the study regard it as speculative - technically feasible but much less likely the more established forcasts for the future climate. Even so, many in the field say the research is a reminder that the planet is definitely getting hotter than that urgent action to cut the gas is the course of warming is needed to limit the damage.
The carbon footprint of the average S.F. Bay Area household (Figure 1) is 44.3 metric tons of CO2 equivalent gases per year (16.3 tons tCO2e per person). This compares to about 50 metric tons for the average U.S. household.
Carbon Clock (Guardian) says remaining carbon budget in CO2e for 2°C is 736 Gt CO2e
World population is 7.6 billion
So that's nearly 100 tonnes CO2e each
Global Carbon Project says CO2 emissions in 2016 were 40+ Gt (including land use change)
Increase by 25% to get 50 Gt CO2e /year
That's 7 tonnes per person which will last 14 years.
A bit longer if reductions happen soon.
As I write this (8th July 2018), the Guardian's Carbon countdown clock gives the remaining catbon budget for staying below 2C as 736.5 billion tonnes of CO2e (CO2- equivalent) considerably less than in the diagram. That's just over 100 tones CO2e for every person on Earth. For a temperature rise of 1.5C the remaining CO2e budget is under 2.2 billion tonnes CO2e or 0.3 tonnes for every person on Earth.
Humanitarian aid has its problems, because it's often used to dump surplus food (so the manufacturers don't lose money) and kills local agriculture. Humanitarian aid is also often used as leverage between warring factions, and it stimulates corruption.
