This week, two short reads.

[SteamyTea]

Earth passes 2°C of warming on hottest day ever recorded

The global average surface temperature was more than 2°C higher than pre-industrial levels on 17 November for the first time since records began, according to provisional data

By Michael Le Page

20 November 2023

 

 

 

Flooding in West Flanders, Belgium, on 17 November – an event occurring more frequently due to climate change

Shutterstock

 

Yet another unwanted temperature record may have been set in 2023. According to a preliminary estimate, the global average surface temperature on 17 November was more than 2°C above pre-industrial levels for the first time.

“Our best estimate is that this was the first day when global temperature was more than 2°C above 1850-1900 (or pre-industrial) levels, at 2.06°C,” tweeted Sam Burgess at the Copernicus Climate Change Service. The finding is provisional, she said.

While exceeding this milestone on one day shows how rapidly the planet is warming as a result of rising greenhouse gas levels, it doesn’t mean that the 2°C warming limit has been breached.

“Hopefully it will prove transitory, but it’s a worrying sign,” tweeted Zeke Hausfather at Berkeley Earth.

The Paris Agreement established a goal to limit the increase in the global average temperature to “well below 2°C above pre-industrial levels” and pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels. It didn’t clearly define what was meant by a rise of 1.5°C or 2°C above pre-industrial levels, but climate scientists generally regard it as being when the long-term average temperature has risen by more than 1.5°C or 2°C compared with the late 19th century. The nature of averages means it won’t be clear when the world passes these limits until several years afterwards.

The definition of pre-industrial matters too. Human-caused warming actually began as early as the mid-18th century, according to Michael Mann at the University of Pennsylvania, and had already raised temperatures by 0.3°C before the late 19th century.

2023 has been the hottest year in recorded history, with numerous maximum temperature records smashed around the world and yet more extreme weather. It could be the first year with an average temperature more than 1.5°C above pre-industrial times.

Next year could be even hotter, in part because the climate has entered an El Niño phase, which transfers more ocean heat into the atmosphere.

However, the long-term global average temperature isn’t expected to exceed 1.5°C of warming until the early 2030s, according to the last report by the Intergovernmental Panel on Climate Change (IPCC).

 

Preventing this would require limiting future emissions to less than 220 gigatonnes of carbon dioxide, an almost impossible goal given that annual global emissions are around 40 gigatonnes and still rising.

The world is currently on course to pass 2°C of warming in the 2040s or 2050s, according to the IPCC.

Global warming does appear to be accelerating, according to Hausfather, but is still in line with the projections of global climate models.

 

 

COP28 must stick to 1.5°C target to save ice sheets, urge scientists

A report warns that 2°C of global warming would mean losing most of the world’s ice sheets and glaciers, leading to catastrophic sea level rise

By Alec Luhn

16 November 2023

 

 

 

Melting of the Greenland ice sheet could result in catastrophic sea level rise

Lukasz Larsson Warzecha/Getty Images

 

The world must stick to its target to limit climate warming to 1.5°C to avoid catastrophic melting of ice sheets and glaciers, according to a report.

The International Cryosphere Climate Initiative (ICCI), a group of scientists who study ice-covered parts of the world, warns that a rise of 2°C would liquidate most tropical and mid-latitude glaciers and set off long-term melting of the Greenland and Antarctic ice sheets, leading to 12 to 20 metres of sea level rise.

In the 2015 Paris Agreement, all countries committed to holding global average temperature to “well below 2°C” over pre-industrial levels and “pursuing efforts” to limit it to 1.5°C. Our still-rising greenhouse gas emissions have already caused almost 1.2°C of warming and put us on track to exceed 3°C.

More than 350 cryosphere scientists have signed an open letter calling on countries to commit to the 1.5°C limit at the upcoming COP28 climate summit in Dubai.

“From the cryosphere point of view, 1.5°C is not simply preferable to 2°C or higher. It is the only option,” Iceland’s prime minister Katrín Jakobsdóttir said in a statement.

Earth’s regions of snow and ice are melting faster than we expected and already approaching tipping points, says Jonathan Bamber at the University of Bristol, UK, who reviewed the ICCI report."

We need to put the brakes on, big time,” says Bamber. “Otherwise, we’re going to see irreversible changes in the polar regions that are going to have global consequences.”

In the past two years, Antarctic sea ice has hit back-to-back record lows, Swiss glaciers have lost 10 per cent of their volume and a winter heatwave melted snow up to 3000 metres high in the Andes.

But 2°C of warming would be much worse, the report warns. The Arctic Ocean would be ice-free almost every summer. Annual carbon emissions from thawing permafrost soils would equal those of the European Union today. And absorption of atmospheric CO2 would permanently acidify polar seas and threaten krill, salmon and king crab.

The Himalayas would lose half their ice, disrupting water supplies for agriculture and hydropower and raising the threat of floods caused by glacial meltwater breaking through a barrier of ice or rock. One such flood killed at least 179 people in Sikkim, India, in October. A study this year found that 15 million people are at risk from sudden glacial floods, mostly in India, Pakistan, Peru and China.

 

“The lakes will start to get larger and larger,” says Tenzing Chogyal Sherpa at the International Centre for Integrated Mountain Development in Nepal, whose hometown of Namche Bazaar, Nepal, was damaged by an outburst flood in 1985. “They’ll be more and more hazardous, and once they get to a point, something can just trigger them, like a landslide.”

Keeping to 1.5°C now requires the world to reach net zero emissions by 2034. Some scientists have argued 1.5°C is dead, while others point to the rapid uptake of solar and wind energy as reason for continued hope.

“It could be that [over 1.5°C] is where we end up,” says Twila Moon at the University of Colorado Boulder, who helped organise the scientists’ letter. “But I think talking ourselves out of rapid change now is selling ourselves short on what is possible because [of] cultural tipping points, social tipping points.”

And even above 1.5°C, “every tenth of the degree counts,” says Bamber.

[FuerteStu]

The problem is, that promises to stick to "1. 5'c" are reliant upon being truthful about emissions, realistic about effectiveness of carbon offsetting, and investment in industries with no track record. 

 

The promise to meet that target is like going into a casino with 5 quid in your pocket, but 5 million in credit available 

 

I think we need to be adopting a very bold "do everything we possibly can in the hopes that some of it will save the planet" 

[ProDave]

59 minutes ago, FuerteStu said:

The problem is, that promises to stick to "1. 5'c" are reliant upon being truthful about emissions, realistic about effectiveness of carbon offsetting, and investment in industries with no track record. 

Like being told Drax burning imported wood on an industrial scale is "CO2 neutral" and is not putting CO2 into the atmosphere.

 

[FuerteStu]

3 minutes ago, ProDave said:

Like being told Drax burning imported wood on an industrial scale is "CO2 neutral" and is not putting CO2 into the atmosphere.

 

The theory is that it's recently grown timber, so over the space of 100 years what was soaked up by the tree, is released. No net increase.. 

 

In fact, over the trees lifespan it's a net decrease as leaves, branches etc end up becoming Soil. 

[gravelrash]

All this talk of CO2 but very little has been said about the ozone hole over the antarctic which is much bigger today than it was 40 years ago...and that is why the ice cap has suddenly increased it melt

[ProDave]

54 minutes ago, FuerteStu said:

The theory is that it's recently grown timber, so over the space of 100 years what was soaked up by the tree, is released. No net increase.. 

 

In fact, over the trees lifespan it's a net decrease as leaves, branches etc end up becoming Soil. 

Yes but what the people that say it is carbon neutral can't grasp is it you left the trees standing, and generated the electricity instead from wind turbines you would stop sending CO2 up the chimney at DRAX and the trees would be absorbing CO2.  Best thing to do with them is leave them standing until you can fell them and make them into something useful that will last a long time keeping that carbon out of the atmosphere.

 

Until the people that plan all this realise this, I have little faith in the plans for net zero actually working even if fully implemented.

[ProDave]

Another off the cuff thing that I have often pondered.  All the talk is of CO2 and greenhouse gasses making the sun warm the earth quicker.

 

What about direct heat?  ALL the heat we put into our homes, regardless of how it is produced, leaks out and directly warms the air.  Ditto any industrial process directly warms the air.

 

I wonder if this direct heating has been included in the models?  Perhaps it has and is insignificant, but it would be reassuring to know it has.  Of course the more insulation we fit to our homes, the less heating they need so the less direct heating there will be.

[SteamyTea]

46 minutes ago, gravelrash said:

All this talk of CO2 but very little has been said about the ozone hole over the antarctic which is much bigger today than it was 40 years ago...and that is why the ice cap has suddenly increased it melt

I take it you read this then.

https://www.noaa.gov/news-release/2023-ozone-hole-ranks-12th-largest-on-record

And then misunderstood it.

 

38 minutes ago, ProDave said:

What about direct heat

I calculated it a while back, can't remember where I posted it.

 

 

[FuerteStu]

6 hours ago, ProDave said:

Another off the cuff thing that I have often pondered.  All the talk is of CO2 and greenhouse gasses making the sun warm the earth quicker.

 

What about direct heat?  ALL the heat we put into our homes, regardless of how it is produced, leaks out and directly warms the air.  Ditto any industrial process directly warms the air.

 

I wonder if this direct heating has been included in the models?  Perhaps it has and is insignificant, but it would be reassuring to know it has.  Of course the more insulation we fit to our homes, the less heating they need so the less direct heating there will be.

I saw a model once that showed mans impact on heat generation was a net loss. Due to the amount of roads, roofs and other surfaces that 'radiated' Heat back out to the void at a higher rate than natural surfaces. 

At the end of the day the energy we generate heat from came from the sun in the first place regardless. (unless you're talking nuclear generation) 

[SteamyTea]

34 minutes ago, FuerteStu said:

unless you're talking nuclear generation

Or gravitational.

  

33 minutes ago, FuerteStu said:

I saw a model once that showed mans impact on heat generation was a net loss. Due to the amount of roads, roofs and other surfaces that 'radiated' Heat back out to the void at a higher rate than natural surfaces. 

I don't think that is right.

Edited November 24, 2023 by SteamyTea

[FuerteStu]

18 minutes ago, SteamyTea said:

 

I don't think that is right.

The model was shared on another forum decades ago, and showed energy retention levels of manmade surfaces from infrared radiation. Natural surfaces absorbed the heat that was then lost through induction, whereas man made surfaces radiated more of the heat back out. 

 

It showed heat maps of urban areas during daylight as well as night. 

 

It seemed logical that the energy from the sun was more likely a net loss in urban areas, and in areas of nature that energy was turned into stored in the form of carbon capture as well as localised heat retained because of canopies of fauna

[SteamyTea]

8 hours ago, FuerteStu said:

It seemed logical that the energy from the sun was more likely a net loss in urban areas,

So urban heat islands are a myth then.

Also, the reflected energy is at a lower frequency and that interacts with the CO₂ in the atmosphere causing heating.

I suspect that model was either wrong or trying to promote something else.

 

https://en.wikipedia.org/wiki/Albedo

[FuerteStu]

1 hour ago, SteamyTea said:

So urban heat islands are a myth then.

Also, the reflected energy is at a lower frequency and that interacts with the CO₂ in the atmosphere causing heating.

I suspect that model was either wrong or trying to promote something else.

 

https://en.wikipedia.org/wiki/Albedo

Interesting read, I was always under the impression that the urban temperature rises was because of city structure trapping the heat in more than surface reflectance. just as a rainforest canopy does. 

Would be interesting to find that original post from years ago and look at it with fresh eyes. 

 

[SteamyTea]

32 minutes ago, FuerteStu said:

I was always under the impression that the urban temperature rises was because of city structure trapping the heat in more than surface reflectance

There are many reasons that urban areas are warmer than surrounding areas.

 

If climate change was solved with single change i.e. 1 technology, or 1 change in behaviour, it would not be a problem.

 

Here is one article that highlights, i think quite nicely, how interactions can be confusing.  Hopefully more research like this will kill the bonkers idea of geoengineering the atmosphere.  Many people still think that CO₂ makes plants grow more, regardless of the temperature they are growing at.  Hopefully the second article will help clear this up.

 

Plants are more productive on weekends thanks to cleaner air

Satellite data from Europe shows that rates of photosynthesis are higher when aerosol levels in the atmosphere are lower, and there is a regular weekly cycle

By Chen Ly

20 November 2023

 

 

 

Aerosol pollution from road vehicles can restrict plants’ capacity for photosynthesis

Aleksei Gorodenkov / Alamy

 

Plants in Europe photosynthesise more at the weekend, probably because there is less pollution in the air.

Photosynthesis is the chemical reaction that plants use to capture energy from the sun and convert carbon dioxide and water into sugar.

With increasing air pollution from wildfires, dust and human activities, Liyin He at the Carnegie Institution for Science in California and her colleagues wanted to see what effect air quality has on photosynthesis.

The team analysed satellite measurements of how much light is emitted by the green pigment chlorophyll in the leaves of plants – which corresponds to how much photosynthesis is occurring – across Europe between 2018 and 2021.

By comparing this with satellite measurements of air pollution over the same period, the team found that photosynthesis rates increased when there were lower levels of aerosols, a type of pollution that includes dust as well as smoke from wildfires and human activity.

These aerosols can stop sunlight from reaching Earth’s surface, which can hamper plants’ photosynthesising capacity. On the other hand, when there is less aerosol pollution in the atmosphere, more sunshine can reach the leaves of plants, says He.

The team found that higher rates of photosynthesis occurred at weekends in 64 per cent of Europe.

“There’s less traffic and industrial activities on the weekend,” says He. “But during the weekdays, the air is dirtier, so we see a strong weekly cycle.”

Furthermore, the team found that aerosol pollution reduced significantly in 2020 compared with other years due to the covid-19 pandemic. As a result, plants were more productive all week long, not just at the weekend.

 

Plants find it harder to absorb carbon dioxide amid global warming

A modelling study suggests that increases in photosynthesis have slowed since 2000, opposing previous research that said this effect would remain strong, helping to absorb CO2 from the atmosphere

By Jason Arunn Murugesu

10 August 2023

 

 

 

Photosynthesis involves plants using the energy from sunlight to produce glucose from carbon dioxide and water

Image navi/QxQ images/Alamy

 

Global warming drying the air may have slowed a rising rate of photosynthesis around the world. With this plant process involving the uptake of carbon dioxide, some researchers hoped that a boost to photosynthesis rates would help to remove the greenhouse gas from the atmosphere, but the latest study suggests this effect has faltered since 2000.

Photosynthesis is the chemical reaction that plants use to convert CO2 and water into carbohydrates. Scientists generally think that a rise in CO2  emissions has been leading to more and more photosynthesis, but Jingfeng Xiao at the University of New Hampshire says that few studies have actually looked into this on a global scale.

To learn more, Xiao and his colleagues analysed ground measurements taken between 1982 and 2016 from sensors scattered around the world that measure fluctuations in CO2 and water vapour in various environments, such as forests and savannahs.

They then used satellite images to estimate plant growth in different locations. Using machine learning, the team combined these datasets to broaden the fluctuation measurements to a global scale.

The models suggest that, on average, increases in global photosynthesis levels have slowed since 2000, despite the amount of CO2 in the atmosphere continuing to rise. This is probably due to the rise in the so-called vapour pressure deficit offsetting some of the increase in CO2, says Xiao. This deficit is a measurement of how dry air is.

The higher the deficit, the more water evaporates off plants’ leaves, in a process called transpiration. A higher rate of transpiration generally supports plant growth, as they suck up water to replace what they lost, resulting in their cells receiving more water and the nutrients it contains, says Xiao.

[gravelrash]

On 24/11/2023 at 13:53, SteamyTea said:

I take it you read this then.

https://www.noaa.gov/news-release/2023-ozone-hole-ranks-12th-largest-on-record

And then misunderstood it.

 

I calculated it a while back, can't remember where I posted it.

 

 

Not that article.... similar but obviously bastardized after reading the noaa.