This week's short read: Will global warming continue after we reach net zero

[SteamyTea]

Environment

Analysis

14 November 2023

By Michael Le Page

 

Will global warming continue even after we hit net-zero emissions?

Understanding how the atmosphere responds to rising and falling carbon emissions is a complex business, and now researchers have found taking longer to reach net zero could see global warming continue afterward.

When will global warming end? It is unclear

 

The longer it takes to reach net zero, the greater the risk that global warming will continue for decades or millennia even after we have cut greenhouse gas emissions, according to an assessment by climate researchers.

 

This means we may have to emit even less carbon dioxide than we thought if we want to limit warming to, say, 2°C, making carbon budgets even smaller than current estimates.

 

“The timing at which we reach net zero is also key,” says Roland Séférian at the National Centre for Meteorological Research (CNRM) in France.

 

Climate modellers once assumed that CO2 levels would remain roughly constant after emissions ceased. In such scenarios, the oceans would continue to warm for several decades, leading to further surface warming.

But more than a decade ago, modellers realised that in fact the oceans will continue to soak up some of the extra CO2, leading to a gradual fall in atmospheric levels and less of the sun’s heat being retained. Recent climate models suggest that, by coincidence, this cooling effect balances out the ocean warming, meaning surface warming halts within a few years of emissions stopping.

 

Not all climate models are the same, however. Standard climate models don’t include all feedbacks, such as how much carbon is taken up by plants on land. More comprehensive “Earth system” models suggest that if, say, emissions stop when the world is 2°C warmer than pre-industrial times, there is a 33 per cent chance that the planet would continue to warm past 2.3°C.

 

Yet this is still not the full story. This is because even the Earth system models don’t include all feedbacks, such as the melting of the ice sheets on Greenland and Antarctica.

 

He and his team have now done a comprehensive assessment of the uncertainties over timescales of decades, centuries and millennia. They looked at 26 factors that could lead to more warming or cooling, from the loss of forests and the melting of permafrost to shrinking ice sheets and changing ocean currents.

 

For around a third of these factors, such as some cloud responses and the extent of sea ice loss, we have no firm knowledge and can only speculate, the researchers say.

 

While some of the factors are expected to cause cooling, there is a general tendency towards additional warming, says team member Joeri Rogelj at Imperial College London.

 

“Peak warming could be higher with additional impacts, damages and challenges,” he says. “It really means that reaching net zero becomes even more important as a milestone.”

Additional warming doesn’t mean unstoppable warming, says Rogelj. It could be prevented by continued carbon removal after net zero, for instance.

 

But in a comment accompanying the paper, Michael Mann at the University of Pennsylvania points out that carbon removal at the scale and speed required for halting warming might not be possible. “What is most urgently required is a rapid phaseout of human-induced activities that produce carbon pollution,” he writes.

 

“I think this is an important paper that emphasises that our understanding of how much the world will warm or cool after we hit net zero is still uncertain,” says Zeke Hausfather of Berkeley Earth.

 

“While our best estimate is that warming will stop when emissions stop, it’s also possible that the world might continue to modestly warm – or modestly cool – after net zero.”

 

Journal reference

 

Frontiers in Science DOI: 10.3389/fsci.2023.1170744

[FuerteStu]

My gut feeling is that we've already pushed the cart over the hill and there's pretty much no way of stopping an extreme future. 

 

Even if we hit net zero tomorrow, there's still so much we've already pumped into the world, that (to use an analogy this forum would understand) the slab has had a hundred years of underfloor heating pumped into it, and even if we find a way of using air con that doesn't make the situation worse, we'll have to have the windows open all year round for a long time to come to deal with it. 

 

Trouble is, that due to the increased sea temperatures, we'll be dealing with a lot more extreme weather events, not just the warmer seasons, but the strongest storms ever recorded and getting worse for decades. 

 

Saying all that, we won't hit net zero for a long time because of corrupt governments and a greedy fossil fuel industry.. So we're actually in it for a lot worse.. When things get bad, modern economics will collapse, the knock on from that will kill more people than the weather will. If you think energy and food are expensive now, you wait to global crop failures and blanket bans on shipping come in. 

 

Anyways, at least we've all got half finished houses to live in! 

[ProDave]

So we have a plan to fix the planet, but even now, nobody knows if the plan we have will work, will it stop warming, will it cause the planet to cool, etc.  So in spite of being certain it is man made CO2 that is causing the problem they don't have a scoobie if stopping all man made CO2 will make any difference or not.

 

No wonder some people cannot take this seriously.

[Marvin]

22 minutes ago, FuerteStu said:

Anyways, at least we've all got half finished houses to live in! 

True but sadly the standard of those properties will not be tough enough for the harsher environment.

 

Drainage designed for 100 year events will have to cope with these events every 10 years.

Brickwork mortar strengths will need to be increased

Roof covering designs will need to be upgraded against higher winds

Basically exposed elements will wear quicker.

 

The grade or wind zones will need upgrading from these:

 

https://klober.co.uk/resource-centre/uk-wind-speed-map

 

Let alone trying to finish your building in adverse weather conditions.... 

 

 

3 hours ago, SteamyTea said:

Will global warming continue even after we hit net-zero emissions?

Yes

 

"What is most urgently required is a rapid phaseout of human-induced activities that produce carbon pollution,”

 

Let me know when this starts!

 

Presently there are too many inconvenient changes to human behaviour required  to achieve the rapid phaseout of human-induced activities that produce carbon pollution which are required to result in net-zero emissions.

 

I think we can only rely on technical developments to offer alternatives that humans will find as acceptable behaviour changes at present.

 

As humans are known for the "needs must" approach to global warming we will not react until the s**t has already hit the fan. Unfortunately there's no instant action giving rise to an instant result in this case. We're not talking about a hair dryer, a shower and a toaster.

 

Elon Musk better get a move on before the weather patterns stop the launching of space rockets!

 

Marvin

 

[FuerteStu]

1 hour ago, ProDave said:

So we have a plan to fix the planet, but even now, nobody knows if the plan we have will work, will it stop warming, will it cause the planet to cool, etc.  So in spite of being certain it is man made CO2 that is causing the problem they don't have a scoobie if stopping all man made CO2 will make any difference or not.

 

No wonder some people cannot take this seriously.

The problem is that those who have the respect to be listen to in terms of solutions are respected scientists. 

 

Scientists do not get respected by theorising untested solutions based upon data sets that are incomplete, with wild variations in possible outcomes due to it being such a complicated modelling. 

 

We end up sound bites from politicians with an agenda, or celebrity driven scientists who quote opinions not science. 

 

All reasonable people agree that we need to do something, but it will come at a huge sacrifice to those who have the power to do it. 

 

There will be a few dead canarys before things change. 

[FuerteStu]

1 hour ago, Marvin said:

 

 

I think we can only rely on technical developments to offer alternatives that humans will find as acceptable behaviour changes at present.

 

I actually think part of the solution might be accidentally presented to ourselves by nature and natural selection. 

 

Perhaps a large algae bloom in the oceans, or Mushroom forest that springs from the retreating permafrost. 

 

The planet has a history of change, and has adapted each time. Granted the current change is massively accelerated by humans, there should still be something out there that benefits and thrives from the excesses, that we could use to ease the symptoms

[Marvin]

25 minutes ago, FuerteStu said:

There will be a few dead canaries before things change. 

I think we are already at that stage. Using your analogy a few mines collapsing killing lots of people will be next. I think the first real pain will be the collapse of food security. 

22 minutes ago, FuerteStu said:

The planet has a history of change, and has adapted each time.

The planets history of change also includes many extinct species not killed off by humans, and the planet adaptions have not always been human friendly!

[Marvin]

6 hours ago, SteamyTea said:

Will global warming continue even after we hit net-zero emissions?

Hi @SteamyTea

Isn't it more important to look at what happens if we don't hit net zero emissions, this being so far away from what is being achieved?

 

The other thing to consider is the effect on the planet due to counter measures taken to hit net-zero emissions.

[Gus Potter]

6 hours ago, FuerteStu said:

My gut feeling is that we've already pushed the cart over the hill and there's pretty much no way of stopping an extreme future.

It is possible but there is a catch.

 

There is to my mind a massive and fundamental niavity in the west where we think that the rest of the world thinks like us. They don't. Ball park figure 2/3 of the world are either driven by autocratic regimes or a form of religion that is fundamentaly not compatible with our western way of life. The last thing on my their minds is the environment and the sooner we wake up to that more chance we will have of saving the world climate wise.. and all the organisms that rely on our fragile ecosystem.

 

I grew up in Arfica, spent lots of time exploring that continent, understanding different cultures.  I have also travelled in the middle east.. I remember when I was a kid turning up in Beruit round about 1976... someone thought it would be a good idea to shoot up the airport terminal and chuck in some hand grenades.. there was dead folk lying about, blood all over the floor and up the walls.. nothing has changed.. except now the weaponry available has become much more devastating. I had the pleasure of briefly meating Idi Amin, he was just a corporal then but became a president. The western world has become beholdened to regimes and religions that are not compatible with our way of western life. We in the west think that by appeasing they will be nice to us.. they won't.

 

In the West we have allowed these countries that don't share out way of life, values of equality and freedom of expression to become our manufacturing base and dominate the supply our some of our base materials we need to manufacture, there will be a price to pay for this... I think we in the west will be invoiced sooner rather than later.

 

I say this as an Engineer.. it's partly logic and partly probability. Until we address the balance politically there is little chance of us saving the plant. The other 2/3 of the world and in particular their leaders will just do enough to make sure that they and their immediate cotary will come out not too bad.. and sod the rest of humanity... and that means pretty much all of us on BH!

 

Sadly it may need a war that significantly reduces the human polulation and that may ultimately save the planet and all the other organisms and animals that share our land, sea and atmosphere.

 

To finish on a high note..yesterday I was chatting to a fisherman pal of mine. He was showing me some of the fish he had caught and released off the the west coast of Scotland. He had caught a 200lb Scate, photographed it and released. The animal was beautiful, enormous, it's colours were so vibrant.. it made me wonder.. why not just leave it alone? he said it was a common scate and these are protected so catch and release.

 

 

 

 

Edited November 19, 2023 by Gus Potter

[Russdl]

I saw a great T-shirt yesterday, it read:

 

There is no

Plan-et B

 

Which puts a spotlight on the problem humanity may be facing but I wouldn’t be at all surprised if that very T-shirt was part of the problem itself. 
 

I didn’t wrestle it off the wearer to check but I suspect that T-shirt has traveled thousands of miles, along with tens of thousands of clones of itself, for no planetary benefit whatsoever. 
 

I wasn’t wearing that T-shirt but I’m sure I have plenty of stuff that has travelled many thousands of miles for my benefit/convenience that I could have lived without. Life would have been a bit more difficult but I suspect I could have got by. 
 

Sent from my phone that I’m pretty sure was made in China.