Saturday, October 26, 2024

Models downplay wrath of what they sow

Models that analyze what is driving up the temperature all too often omit specific sources, or when included, models all too often downplay their contribution. Accordingly, policies that are promoted based on such models are all too often ineffective or even counter-productive. 

Methane is all too often referred to as 'natural gas' originating from wetlands, swamps, cows and pigs, as if calling methane 'natural' implied that human activities were not responsible for such emissions. Moreover, people with vested interests all too often suggest that such 'natural emissions' should be captured and used for heating, cooking or industrial purposes, to offset 'human emissions'. Similarly, forest fires are all too often referred to as 'wildfires', as if human activities were not responsible for them. 

The compilation of images below shows forest fires as the largest source of carbon dioxide emissions on October 26, 2024. An image of carbon monoxide is also added (bottom right), as carbon monoxide is an indicator of forest fires. Carbon monoxide is also important since it is a precursor of tropospheric ozone and carbon monoxide depletes tropospheric hydroxyl radicals, thus extending methane's lifetime. 


The methane image (top right) shows a high presence of methane in northern Europe. The cause for this is the high temperatures anomaly in northern Europe on October 26, 2024, resulting in strong decomposition of vegetation, which comes with high emissions of carbon dioxide, carbon monoxide and methane. 


The high temperatures anomaly in northern Europe is illustrated by the above image. The image also illustrates polar amplification of the temperature rise, one of the mechanisms that drives up the temperature rise. Numerous mechanisms driving up the temperature rise are discussed in an earlier post that warns about a Double Blue Ocean Event. Thawing permafrost can cause huge emissions of carbon dioxide (CO₂), methane and nitrous oxide. 

[ from earlier post ]
Rising emissions could originate from many sources, the more so as more sinks turn into sources.
[ from earlier post ]
Many models go back only to 1750, many even use an earlier base, as if concentrations of greenhouse gases only started to rise then. 

The image on the right shows IPCC and WMO values for the rise of methane (CH₄), carbon dioxide (CO₂) and nitrous oxide (N₂O) from 1750. The image shows that: 
- Methane rose to 265% its 1750 value. - Carbon dioxide rose to 151% its 1750 value.
- Nitrous oxide rose to 125% its 1750 value.

Note that values for methane as low as 550 ppb and carbon dioxide as low as 260 ppm have been found in ice cores corresponding with periods thousands of years ago, as illustrated by the image below, from the pre-industrial page, based on Ruddiman et al. (2015). 


According to the Met Office, climate sensitivity is typically defined as the global temperature rise following a doubling of CO₂ concentration in the atmosphere compared to pre-industrial levels. Pre-industrial CO₂ was about 260 parts per million (ppm), so a doubling would be at roughly 520 ppm.

A recent study found that doubling the atmospheric CO₂ levels could cause an increase in Earth’s average temperature of 7 to 14°C (13 to 25.2°F). In the video below, Guy McPherson discusses the study.


How fast could a rise to 520 ppm CO₂ unfold? Models typically put 520 ppm CO₂ far away in the future. The image below shows an analysis based on August 2009 through July 2024 data that has a trend added pointing at 520 ppm CO₂ getting crossed in 2029 and 1200 ppm CO₂ getting crossed in early 2035. In other words, the clouds tipping point could get crossed in early 2035 due to rising CO₂ alone, and because this tipping point is measured in CO₂e, this could occur well before 2035 when including the impact of feedbacks and further mechanisms.

[ from earlier post ]

Another way the danger of rising temperatures is all too often downplayed is to suggest that many feedbacks work only over very long timescales. This narrative may be convenient for politicians who rarely bother about what happens beyond the next election. However, as discussed in a recent post, there are many mechanisms that can push up the temperature rapidly, adding up to a potential rise of more than 18°C within years.

Climate Emergency Declaration

Instead of omitting them, all mechanisms driving up the temperature should be fully included in an action plan that seeks to improve the situation. Multiple policy instruments and combinations of policy instruments should be considered for implementation, preferably through local feebates. 

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.



Links

• Copernicus - Climate Pulse
https://atmosphere.climate.copernicus.eu

• Climate Reanalyzer 
https://climatereanalyzer.org

• World Meteorological Organization (WMO) - Greenhouse Gas Bulletin - No. 20 – 28 October 2024

• Double Blue Ocean Event 2025? 
https://arctic-news.blogspot.com/2024/10/double-blue-ocean-event-2025.html

• Continuous sterane and phytane δ13C record reveals a substantial pCO2 decline since the mid-Miocene - by Caitlyn R. Witkowski et al. (2024) 



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