this post was submitted on 06 Jun 2024
61 points (100.0% liked)

Climate - truthful information about climate, related activism and politics.

5243 readers
303 users here now

Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.

As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades: Graph of temperature as observed with significant warming, and simulated without added greenhouse gases and other anthropogentic changes, which shows no significant warming

How much each change to the atmosphere has warmed the world: IPCC AR6 Figure 2 - Thee bar charts: first chart: how much each gas has warmed the world. About 1C of total warming. Second chart: about 1.5C of total warming from well-mixed greenhouse gases, offset by 0.4C of cooling from aerosols and negligible influence from changes to solar output, volcanoes, and internal variability. Third chart: about 1.25C of warming from CO2, 0.5C from methane, and a bunch more in small quantities from other gases. About 0.5C of cooling with large error bars from SO2.

Recommended actions to cut greenhouse gas emissions in the near future:

Anti-science, inactivism, and unsupported conspiracy theories are not ok here.

founded 1 year ago
MODERATORS
[email protected]
61
During Year of Extremes, Carbon Dioxide Levels Surge Faster than Ever (today.ucsd.edu)
submitted 5 months ago by [email protected] to c/[email protected]
9 comments fedilink hide all child comments
 

“Not only is CO2 now at the highest level in millions of years, it is also rising faster than ever. Each year achieves a higher maximum due to fossil-fuel burning, which releases pollution in the form of carbon dioxide into the atmosphere,” said Ralph Keeling, director of the Scripps CO2 program that manages the institution’s 56-year-old measurement series. “Fossil fuel pollution just keeps building up, much like trash in a landfill.”

The record two-year growth rate observed from 2022 to 2024 is likely a result of sustained high fossil fuel emissions combined with El Niño conditions limiting the ability of global land ecosystems to absorb atmospheric CO2, said John Miller, a carbon cycle scientist with the Global Monitoring Laboratory.

The Mauna Loa data, together with measurements from sampling stations around the world, are incorporated into the Global Greenhouse Gas Reference Network, a foundational research dataset for international climate scientists and a benchmark for policymakers attempting to address the causes and impacts of climate change.

you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 5 points 5 months ago* (last edited 5 months ago) (2 children)

Global directly-anthropogenic CO2 emissions - things we measure and attribute to countries - have been flat in the period 2019-23 (except for covid dip), and maybe falling this year (due to changes in China). However there are also climate -> carbon feedbacks. The most obvious are forest fires which tend to peak during El Niño years (it's a repeating pattern - I even remember 1998 seeming bad). Heating also enhances respiration by bugs in soils, and reduces the solubility of CO2 in seawater - the ocean is the largest and most long-term CO2 sink. El Niño also changes ocean circulation temporarily, but I forget which way this impacts CO2 (it's not trivial - you have to think about the history and future of large patches of water).
So, if known emissions are flat, but there is a record increase in the atmosphere, that means those feedbacks are worse. It takes a while to disentangle the factors, but this is not a surprise to me.

[–] [email protected] 2 points 5 months ago (1 children)

So now we need to wait and see if it will slowly fall back or if we hit a runaway situation, basically?

[–] [email protected] 3 points 5 months ago

Well, maybe not just wait ... Some factors will fall back - e.g. El Niño is a cycle, so are sunspots, ocean patches go round in (big-slow) loops, forests can run out of tinder (for a while). But to be sure to tip the balance of those climate-carbon feedbacks we need to get the temperature down - this could be done quicker by focusing especially on emissions of shorter-lived gases - mainly methane. Cutting out aviation-induced cirrus might also help to cancel some of the warming we got from cutting shipping sulphate - the opposite effect is because low clouds cause net cooling, high clouds cause net warming (depending on angle of sun etc. ...). The good news is that models already include most of these factors, the bad news is that models say we have to cut emissions much faster than we do.

[–] [email protected] 2 points 5 months ago

Global directly-anthropogenic CO2 emissions - things we measure and attribute to countries - have been flat in the period 2019-23 (except for covid dip)

Could you provide a link (or more) that support this claim?

The article posted here tells a very different story and has many links to support what they say.

When combined with 2023’s increase of 3.0 ppm, 2022 to 2024 has seen the largest two-year jump in the May peak of the Keeling Curve in the NOAA record. For Scripps, the two-year jump tied a previous record set in 2020.

“Not only is CO2 now at the highest level in millions of years, it is also rising faster than ever. Each year achieves a higher maximum due to fossil-fuel burning, which releases pollution in the form of carbon dioxide into the atmosphere,” said Ralph Keeling, director of the Scripps CO2 program that manages the institution’s 56-year-old measurement series.

The record two-year growth rate observed from 2022 to 2024 is likely a result of ...