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The contents of the Carbon neutrality page were merged into Net zero emissions on August 23, 2023. For the contribution history and old versions of the redirected page, please see its history; for the discussion at that location, see its talk page. |
On 29 August 2023, it was proposed that this article be moved from Net zero to Net zero emissions. The result of the discussion was moved. |
Hello! Asked to give feedback as part of an edit-a-thon.
Hi @femke, @Clayoquot, and anyone else interested:
I have created a draft of a new carbon neutrality page at the link below. It is based on the original page, but with some significant edits to improve clarity and accuracy. I also took out parts that were unique to Net Zero, which hopefully could have a new page. I still need to add some citations to it, but it is almost done.
I was wondering if you could please take a look and let me know what you think or edit it directly. If it looks good, I will attempt to upload it to the original carbon neutrality page.
/info/en/?search=User:Leanunu/sandbox#Standards_and_Certifications_Bodies Leanunu ( talk) 18:08, 21 June 2023 (UTC)
Here in Turkey our country goal is net zero but I understand China’s goal is carbon neutrality. Perhaps China is the only such country and it is as yet unclear whether they will change it to net zero? Will you discuss countries in this article? Chidgk1 ( talk) 19:59, 29 March 2023 (UTC)
Can you,
User:Shanag888, please also do some work on the
carbon neutrality article now to ensure the two articles interlink well with each other? Which is the parent article and which is the sub article, does this come out clearly yet? For example I find the first sentence of the
carbon neutrality article confusing now: Carbon neutrality is a state of net zero
carbon dioxide emissions
. Should the net zero that appears in that first sentence now be wikilinked to
net zero? If not, can there be a better first sentence?
EMsmile (
talk) 09:13, 1 August 2023 (UTC)
Shanag888, to answer your question above on what to do next, I suggest finding some high-quality sources on definitions of carbon neutrality and adding those definitions to Carbon neutrality. It's usually easiest to start by writing a Definitions section and then summarizing that for the lead. Some definitions address issues such as scope, stringency, permanence of removals, and transparency, whereas simpler definitions don't mention these issues at all. I think it's important to say that there are varying definitions and to introduce these issues. If I understand things correctly, the distinction between the carbon neutrality and net zero standards will make sense only after the reader understands the issues covered in the detailed definitions that are published in the standards.
The lead section of Carbon neutrality is currently very confusing IMO - its first two sentences give a definition that's the same as the definition of net zero, and then it says net zero is "broader" but I can't see how anything can be broader than what the first two sentences say. Clayoquot ( talk | contribs) 14:46, 2 August 2023 (UTC)
I agree with the suggestions made above. A title of
net zero and carbon neutrality (or
net zero and climate neutrality?) would also work for me. Or is there an overarching term for both of them? As I was still confused about what's what, I went to Chat-GPT and asked there: "what's the difference between climate neutral and net zero?" (one could play around with different prompts to get better answers). It said, amongst other things: In essence, while both terms involve reducing emissions and offsetting impacts, "climate neutral" focuses on balancing the emissions of a specific activity or entity, while "net zero" is a broader goal that aims to balance all emissions on a larger scale, such as a national economy or global emissions. The transition to a net zero state is considered crucial in mitigating the effects of climate change and limiting global warming. It's important to note that achieving these goals requires genuine efforts to reduce emissions at their source rather than relying solely on offsets, as well as the development and implementation of sustainable practices, technologies, and policies across various sectors.
. I feel a bit sad / surprised / annoyed / amused that Chat-GPT seems to do a better job for explaining these two terms than the two Wikipedia articles do (??)... Let's change that!
EMsmile (
talk) 07:42, 11 August 2023 (UTC)
I'm seeing a wp:rough consensus above that one article should cover both net zero and carbon neutrality and am in the process of merging Carbon neutrality into Net zero. For reference, I have copied the current Carbon neutrality article here: Talk:Net zero/Carbon neutrality August 23 2023. I do not see a consensus regarding article title, so I am leaving it "Net zero" for now and we can continue discussion if anyone wishes to change it. Personally I think "Net zero" works. Regarding the differences between the meanings of carbon neutrality and net zero, I have added sourcing which demonstrates that these terms are often used interchangeably. "They are the same" is a point of view held by some reliable sources, and "they are different" is a point of view held by others. As a neutral encyclopedia we try to describe different reliably-published points of view without bias. I've tried to do that and to make the "they are different" point of view clear. If you can think of a way to improve on it, please do. Clayoquot ( talk | contribs) 17:37, 23 August 2023 (UTC)
I think Net zero is a much, much stronger article than Carbon neutrality was. Leanunu, Our2050World, Shanag888 and NetZeroPhysicist brought in first-rate sources and showed us how Wikipedia can cover this topic in a way that invites critical thinking around net zero claims. Thank you! Clayoquot ( talk | contribs) 19:43, 23 August 2023 (UTC)
I've finished copying in everything from Carbon neutrality that I think should be merged. I recommend not copying the Examples of pledges section. Having a section like this made sense in 2014 when there were just a handful of pledges; now there are thousands. The section makes attempts to summarize the decarbonization strategies of entire countries in a few sentences, which is really difficult to do well while avoiding greenwashing. Clayoquot ( talk | contribs) 18:07, 23 August 2023 (UTC)
I am wondering a little about that long section on Examples of pledges. Some of that had been added quite recently. I wonder if there aren't at least some sentences there which could still be utilised in the new article. Or perhaps they should instead be moved to the relevant country articles, like climate change in Europe. EMsmile ( talk) 21:20, 23 August 2023 (UTC)
As of October 2021 [update], numerous countries/nations have pledged carbon neutrality, including: [1] [2]EMsmile ( talk) 08:53, 25 August 2023 (UTC)
References
I've removed the following content. I'm sorry, but I'm finding it so technical and dense that I believe very few readers will understand it. I don't think this level of detail is necessary in order for the reader to appreciate the need for net zero. Clayoquot ( talk | contribs) 16:12, 21 August 2023 (UTC)
Extended content
|
---|
The context of this sentence is that the anthropogenic (human-induced) change in global average surface temperature over a multi-decade time-period is given, to a good approximation, by [1] where the first term indicates CO2-induced warming and the second term indicates warming due to the net impact of other anthropogenic drivers such as emissions of methane, nitrous oxide or aerosol precursors.
The scientific justification of net zero is summarised earlier in the Summary for Policymakers of SR1.5, thus: "Reaching and sustaining net zero global anthropogenic CO2 emissions and declining net non-CO2 radiative forcing would halt anthropogenic global warming on multi-decadal timescales (high confidence)." Of the variables in this equation, is the average rate of CO2 emissions over this time-period from geological sources (such as fossil fuel combustion and cement production, minus any engineered CO2 removed to geological storage). is the corresponding average rate of CO2 emissions from land-use change, agriculture and forestry minus CO2 removed by active interventions such as afforestation and nature-based solutions: it does not include CO2 uptake by the biosphere that occurs as a result of past CO2 emissions due to natural processes such as CO2 fertilisation. is cumulative CO2 emissions since pre-industrial times up to the middle of this time-period. is the change in net non-CO2 radiative forcing over this time-period (shorter timescale adjustments can be accounted for by taking as the difference between the decade prior to the beginning and decade prior to the end of the time-period) and is the average non-CO2 radiative forcing over this time-period. Approximately constant coefficients include , the Transient Climate Response to Emissions, about 0.45 °C per TtCO2 (trillion tonnes of CO2); is the Transient Climate Response to Forcing, about 0.49 Watts per m2 per TtCO2; is the fractional Rate of Adjustment to Constant Forcing, or the fractional rate at which global average surface temperature would continue to increase over the decades following a forcing stabilisation, which is about 0.3% per year; and is the fractional Rate of Forcing Decline under Zero CO2 Emissions, also about 0.3% per year. The fact that means that the third term in the square brackets is approximately zero, and hence that net zero CO2 emissions, , and declining net non-CO2 radiative forcing, , is sufficient to halt global warming, , justifying the SR1.5 statement. Despite this cancellation, the term represents an important process. It is the "passive" uptake of CO2 by the biosphere and oceans that would continue for decades even if all human activity were to cease (called passive because it requires no active human intervention, although it might require very active protection of natural carbon sinks). |
net zero requires atmospheric concentrations of carbon dioxide to fallyou meant to say "net zero will cause atmospheric concentrations of carbon dioxide to fall" or "stopping warming requires atmospheric concentrations of carbon dioxide to fall", right? Clayoquot ( talk | contribs) 00:52, 13 September 2023 (UTC)
I removed or condensed the following. Some of this could be appropriate for a future article called, say, Scientific basis of net zero emissions. I really like NetZeroPhysicist's point about making a distinction between net zero emissions and stabilising atmospheric concentrations of greenhouse gases. In my rewrite I highlighted this distinction.
Extended content
|
---|
Why net zero is not the same as climate equilibriumThe scientific justification of net zero is summarised earlier in the Summary for Policymakers of SR1.5, thus: "Reaching and sustaining net zero global anthropogenic CO2 emissions and declining net non-CO2 radiative forcing would halt anthropogenic global warming on multi-decadal timescales (high confidence)." To understand the significance of this conclusion, it helps to recall the focus of climate policy before the introduction of the concept of net zero, which was, in the words of Article 2 of the 1992 Rio Convention, "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system". The figure shows, using a simple climate model, [2] that emissions (top left panel) can continue at a reduced level for many centuries after stabilization of CO2 concentrations (hence early climate policies like the 2008 UK Climate Change Act only committed to 50-80% emission reductions), but this fails to halt global warming (bottom left panel). Global average surface temperatures continue to increase for many centuries due to the gradual adjustment of deep ocean temperatures. The eventual warming reached is highly uncertain due to uncertainty in equilibrium climate sensitivity. In 2009, it was recognised [3] that reducing emissions to net zero (top right panel) allowed CO2 concentrations (middle right panel), and hence CO2-induced radiative forcing, to decline just fast enough to compensate for this deep ocean adjustment to give approximately constant global average surface temperatures on multi-decade to century timescales (bottom right panel). The following equation is helpful to understand the reason net zero CO2 emissions are needed to halt global warming, and that net zero is not the same as climate equilibrium. The human-induced change in global average surface temperature over a multi-decade time-period is given, to a good approximation, by [4] where the first term indicates CO2-induced warming and the second term indicates warming due to the net impact of other human-induced climate drivers such as methane, nitrous oxide or aerosols.
The variables in this equation (which depend on human activity) are as follows: is the average rate of CO2 emissions over this time-period from geological sources (such as fossil fuel combustion and cement production, minus any engineered CO2 removed to geological storage). is the corresponding average rate of CO2 emissions from land-use change, agriculture and forestry minus CO2 removed by active interventions such as afforestation and nature-based solutions: it does not include CO2 uptake by the biosphere that occurs as a result of past CO2 emissions due to natural processes such as CO2 fertilisation. is cumulative CO2 emissions since pre-industrial times up to the middle of this time-period. is the change in, and is the average, net non-CO2 radiative forcing over this time-period. The coefficients in this equation (which are approximately constant) are as follows: is the Transient Climate Response to Emissions, about 0.45 °C per TtCO2 (trillion tonnes of CO2); is the Transient Climate Response to Forcing, about 0.49 Watts per m2 per TtCO2; is the fractional Rate of Adjustment to Constant Forcing, which is about 3% per decade; and is the fractional Rate of Forcing Decline under Zero CO2 Emissions, also about 3% per decade. The fact that means that reducing net CO2 emissions, , to zero would stop CO2 emissions from causing any additional global warming, although warming caused by past CO2 emissions would still persist. The second term shows that net non-CO2 radiative forcing needs to decline at a rate to stop non-CO2 climate pollutants causing additional global warming: hence the SR1.5 statement above. Although often neglected (because it is approximately balanced by the term), the term is important. It is the "passive" uptake of CO2 by the biosphere and oceans that would continue for decades even if all human activity were to cease. This passive uptake, which is not classified as a directly human-caused removal by the IPCC, [5] draws atmospheric CO2 concentrations down (middle right panel of the figure) just fast enough to stop any further global surface warming under net zero CO2 emissions. Hence net zero does not refer to a stable climate equilibrium state, but a dynamic balance between the ongoing adjustment of the global carbon cycle and ocean heat content. Although global average surface temperatures would stop rising, other aspects of the climate system, such as sea level, would continue to change for centuries after net zero emissions is achieved. The size of the term (approximately one quarter of current emissions after net zero is achieved in a 1.5-2 °C scenario) demonstrates the importance of protecting natural carbon sinks in a warming climate. |
Clayoquot ( talk | contribs) 23:30, 9 September 2023 (UTC)
References
{{
cite journal}}
: CS1 maint: unflagged free DOI (
link)
Should we add a short description? I hesitate to set one up and am mindful of long discussions like what we had on the talk page of sustainable energy. Or maybe it's easier than I am thinking. EMsmile ( talk) 21:13, 23 August 2023 (UTC)
The result of the move request was: moved. ( closed by non-admin page mover) EggRoll97 ( talk) 17:49, 5 September 2023 (UTC)
Net zero → Net zero emissions – Following from discussion above, the current title is just a mathematical term that does not directly communicate that the article is about climate change. The proposed title would provide natural disambiguation, as well as sounding less slogan-y. {{u| Sdkb}} talk 16:07, 29 August 2023 (UTC)
it's crucial to normalize that term and concept in order for the energy transition to be successfulOur goal on Wikipedia is not to make the energy transition successful. {{u| Sdkb}} talk 14:26, 31 August 2023 (UTC)
In paragraph 2: "Country-level net zero targets now cover 92% of global GDP, 88% of emissions and 89% of the world population"
In paragraph 3: "While 61% of global carbon dioxide emissions are covered by some sort of net zero target"
These seem to be at odds (88% of emissions and 61% of carbon dioxide emissions). What's the reason for this difference and can this be briefly explained? Markmuetz ( talk) 09:14, 12 September 2023 (UTC)
I copied the following post from my talk page as it would benefit from input from more people. Clayoquot ( talk | contribs) 17:22, 15 September 2023 (UTC)
Hello, I just saw your reply to my comment on the talk page for Net zero emissions saying "Adding “CO2” or “carbon “ to the title would not be accurate. Limiting climate change requires net zero emissions of all greenhouse gases...". That part of the discussion was closed so I just thought I'd explain here that this is not the case. See e.g. https://www.oxfordmartin.ox.ac.uk/news/2018-news-climate-pollutants-gwp/, https://www.nature.com/articles/s41612-018-0026-8. Pagw ( talk) 08:00, 12 September 2023 (UTC)
Just a heads-up to save embarassment: a report by issued this week by Civitas, a London think tank, has been cited heavily by Conservative-aligned media in the UK. Serious errors in methodology have been identified in the report (for example, confusing megawatts with megawatt-hours, billions with trillions) so neither it nor the media that reported it should be considered a reliable source. [1] -- 𝕁𝕄𝔽 ( talk) 16:12, 29 September 2023 (UTC)
References
𝕁𝕄𝔽 ( talk) 16:12, 29 September 2023 (UTC)
I'm wanting to add the UN's minimum requirements for net-zero pledges within their "race to zero" campaign, termed "starting line criteria". However, this article is not specific solely to the U.N. criteria, even if leaning heavily on it (or so it appears).
If the minimum requirements for "race to zero" are added, as well as what percent of orgs are meeting/not meeting them, where would that be best placed within the article? Pyrrho the Skipper ( talk) 02:02, 6 November 2023 (UTC)
For anyone watching this page, could you please have a look at the
low-carbon economy article as well, and check if the two articles interlink well? Do they duplicate some content? Are the methods for getting to a
low-carbon economy the same as those to get to
net zero emissions? Is
net zero emissions really just the "more extreme" / "more ideal" case compared to
low-carbon economy? And how do we define "low"? See also talk page there. For example, I have written there in the lead this sentence, do you agree?: An even more ambitious target than low-carbon economies are zero-carbon economies with
net zero emissions. An example are
zero-carbon cities.
EMsmile (
talk) 09:15, 12 January 2024 (UTC)
This is the
talk page for discussing improvements to the
Net zero emissions article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
This article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||||||||||||||||||
|
Daily pageviews of this article
A graph should have been displayed here but
graphs are temporarily disabled. Until they are enabled again, visit the interactive graph at
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The contents of the Carbon neutrality page were merged into Net zero emissions on August 23, 2023. For the contribution history and old versions of the redirected page, please see its history; for the discussion at that location, see its talk page. |
On 29 August 2023, it was proposed that this article be moved from Net zero to Net zero emissions. The result of the discussion was moved. |
Hello! Asked to give feedback as part of an edit-a-thon.
Hi @femke, @Clayoquot, and anyone else interested:
I have created a draft of a new carbon neutrality page at the link below. It is based on the original page, but with some significant edits to improve clarity and accuracy. I also took out parts that were unique to Net Zero, which hopefully could have a new page. I still need to add some citations to it, but it is almost done.
I was wondering if you could please take a look and let me know what you think or edit it directly. If it looks good, I will attempt to upload it to the original carbon neutrality page.
/info/en/?search=User:Leanunu/sandbox#Standards_and_Certifications_Bodies Leanunu ( talk) 18:08, 21 June 2023 (UTC)
Here in Turkey our country goal is net zero but I understand China’s goal is carbon neutrality. Perhaps China is the only such country and it is as yet unclear whether they will change it to net zero? Will you discuss countries in this article? Chidgk1 ( talk) 19:59, 29 March 2023 (UTC)
Can you,
User:Shanag888, please also do some work on the
carbon neutrality article now to ensure the two articles interlink well with each other? Which is the parent article and which is the sub article, does this come out clearly yet? For example I find the first sentence of the
carbon neutrality article confusing now: Carbon neutrality is a state of net zero
carbon dioxide emissions
. Should the net zero that appears in that first sentence now be wikilinked to
net zero? If not, can there be a better first sentence?
EMsmile (
talk) 09:13, 1 August 2023 (UTC)
Shanag888, to answer your question above on what to do next, I suggest finding some high-quality sources on definitions of carbon neutrality and adding those definitions to Carbon neutrality. It's usually easiest to start by writing a Definitions section and then summarizing that for the lead. Some definitions address issues such as scope, stringency, permanence of removals, and transparency, whereas simpler definitions don't mention these issues at all. I think it's important to say that there are varying definitions and to introduce these issues. If I understand things correctly, the distinction between the carbon neutrality and net zero standards will make sense only after the reader understands the issues covered in the detailed definitions that are published in the standards.
The lead section of Carbon neutrality is currently very confusing IMO - its first two sentences give a definition that's the same as the definition of net zero, and then it says net zero is "broader" but I can't see how anything can be broader than what the first two sentences say. Clayoquot ( talk | contribs) 14:46, 2 August 2023 (UTC)
I agree with the suggestions made above. A title of
net zero and carbon neutrality (or
net zero and climate neutrality?) would also work for me. Or is there an overarching term for both of them? As I was still confused about what's what, I went to Chat-GPT and asked there: "what's the difference between climate neutral and net zero?" (one could play around with different prompts to get better answers). It said, amongst other things: In essence, while both terms involve reducing emissions and offsetting impacts, "climate neutral" focuses on balancing the emissions of a specific activity or entity, while "net zero" is a broader goal that aims to balance all emissions on a larger scale, such as a national economy or global emissions. The transition to a net zero state is considered crucial in mitigating the effects of climate change and limiting global warming. It's important to note that achieving these goals requires genuine efforts to reduce emissions at their source rather than relying solely on offsets, as well as the development and implementation of sustainable practices, technologies, and policies across various sectors.
. I feel a bit sad / surprised / annoyed / amused that Chat-GPT seems to do a better job for explaining these two terms than the two Wikipedia articles do (??)... Let's change that!
EMsmile (
talk) 07:42, 11 August 2023 (UTC)
I'm seeing a wp:rough consensus above that one article should cover both net zero and carbon neutrality and am in the process of merging Carbon neutrality into Net zero. For reference, I have copied the current Carbon neutrality article here: Talk:Net zero/Carbon neutrality August 23 2023. I do not see a consensus regarding article title, so I am leaving it "Net zero" for now and we can continue discussion if anyone wishes to change it. Personally I think "Net zero" works. Regarding the differences between the meanings of carbon neutrality and net zero, I have added sourcing which demonstrates that these terms are often used interchangeably. "They are the same" is a point of view held by some reliable sources, and "they are different" is a point of view held by others. As a neutral encyclopedia we try to describe different reliably-published points of view without bias. I've tried to do that and to make the "they are different" point of view clear. If you can think of a way to improve on it, please do. Clayoquot ( talk | contribs) 17:37, 23 August 2023 (UTC)
I think Net zero is a much, much stronger article than Carbon neutrality was. Leanunu, Our2050World, Shanag888 and NetZeroPhysicist brought in first-rate sources and showed us how Wikipedia can cover this topic in a way that invites critical thinking around net zero claims. Thank you! Clayoquot ( talk | contribs) 19:43, 23 August 2023 (UTC)
I've finished copying in everything from Carbon neutrality that I think should be merged. I recommend not copying the Examples of pledges section. Having a section like this made sense in 2014 when there were just a handful of pledges; now there are thousands. The section makes attempts to summarize the decarbonization strategies of entire countries in a few sentences, which is really difficult to do well while avoiding greenwashing. Clayoquot ( talk | contribs) 18:07, 23 August 2023 (UTC)
I am wondering a little about that long section on Examples of pledges. Some of that had been added quite recently. I wonder if there aren't at least some sentences there which could still be utilised in the new article. Or perhaps they should instead be moved to the relevant country articles, like climate change in Europe. EMsmile ( talk) 21:20, 23 August 2023 (UTC)
As of October 2021 [update], numerous countries/nations have pledged carbon neutrality, including: [1] [2]EMsmile ( talk) 08:53, 25 August 2023 (UTC)
References
I've removed the following content. I'm sorry, but I'm finding it so technical and dense that I believe very few readers will understand it. I don't think this level of detail is necessary in order for the reader to appreciate the need for net zero. Clayoquot ( talk | contribs) 16:12, 21 August 2023 (UTC)
Extended content
|
---|
The context of this sentence is that the anthropogenic (human-induced) change in global average surface temperature over a multi-decade time-period is given, to a good approximation, by [1] where the first term indicates CO2-induced warming and the second term indicates warming due to the net impact of other anthropogenic drivers such as emissions of methane, nitrous oxide or aerosol precursors.
The scientific justification of net zero is summarised earlier in the Summary for Policymakers of SR1.5, thus: "Reaching and sustaining net zero global anthropogenic CO2 emissions and declining net non-CO2 radiative forcing would halt anthropogenic global warming on multi-decadal timescales (high confidence)." Of the variables in this equation, is the average rate of CO2 emissions over this time-period from geological sources (such as fossil fuel combustion and cement production, minus any engineered CO2 removed to geological storage). is the corresponding average rate of CO2 emissions from land-use change, agriculture and forestry minus CO2 removed by active interventions such as afforestation and nature-based solutions: it does not include CO2 uptake by the biosphere that occurs as a result of past CO2 emissions due to natural processes such as CO2 fertilisation. is cumulative CO2 emissions since pre-industrial times up to the middle of this time-period. is the change in net non-CO2 radiative forcing over this time-period (shorter timescale adjustments can be accounted for by taking as the difference between the decade prior to the beginning and decade prior to the end of the time-period) and is the average non-CO2 radiative forcing over this time-period. Approximately constant coefficients include , the Transient Climate Response to Emissions, about 0.45 °C per TtCO2 (trillion tonnes of CO2); is the Transient Climate Response to Forcing, about 0.49 Watts per m2 per TtCO2; is the fractional Rate of Adjustment to Constant Forcing, or the fractional rate at which global average surface temperature would continue to increase over the decades following a forcing stabilisation, which is about 0.3% per year; and is the fractional Rate of Forcing Decline under Zero CO2 Emissions, also about 0.3% per year. The fact that means that the third term in the square brackets is approximately zero, and hence that net zero CO2 emissions, , and declining net non-CO2 radiative forcing, , is sufficient to halt global warming, , justifying the SR1.5 statement. Despite this cancellation, the term represents an important process. It is the "passive" uptake of CO2 by the biosphere and oceans that would continue for decades even if all human activity were to cease (called passive because it requires no active human intervention, although it might require very active protection of natural carbon sinks). |
net zero requires atmospheric concentrations of carbon dioxide to fallyou meant to say "net zero will cause atmospheric concentrations of carbon dioxide to fall" or "stopping warming requires atmospheric concentrations of carbon dioxide to fall", right? Clayoquot ( talk | contribs) 00:52, 13 September 2023 (UTC)
I removed or condensed the following. Some of this could be appropriate for a future article called, say, Scientific basis of net zero emissions. I really like NetZeroPhysicist's point about making a distinction between net zero emissions and stabilising atmospheric concentrations of greenhouse gases. In my rewrite I highlighted this distinction.
Extended content
|
---|
Why net zero is not the same as climate equilibriumThe scientific justification of net zero is summarised earlier in the Summary for Policymakers of SR1.5, thus: "Reaching and sustaining net zero global anthropogenic CO2 emissions and declining net non-CO2 radiative forcing would halt anthropogenic global warming on multi-decadal timescales (high confidence)." To understand the significance of this conclusion, it helps to recall the focus of climate policy before the introduction of the concept of net zero, which was, in the words of Article 2 of the 1992 Rio Convention, "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system". The figure shows, using a simple climate model, [2] that emissions (top left panel) can continue at a reduced level for many centuries after stabilization of CO2 concentrations (hence early climate policies like the 2008 UK Climate Change Act only committed to 50-80% emission reductions), but this fails to halt global warming (bottom left panel). Global average surface temperatures continue to increase for many centuries due to the gradual adjustment of deep ocean temperatures. The eventual warming reached is highly uncertain due to uncertainty in equilibrium climate sensitivity. In 2009, it was recognised [3] that reducing emissions to net zero (top right panel) allowed CO2 concentrations (middle right panel), and hence CO2-induced radiative forcing, to decline just fast enough to compensate for this deep ocean adjustment to give approximately constant global average surface temperatures on multi-decade to century timescales (bottom right panel). The following equation is helpful to understand the reason net zero CO2 emissions are needed to halt global warming, and that net zero is not the same as climate equilibrium. The human-induced change in global average surface temperature over a multi-decade time-period is given, to a good approximation, by [4] where the first term indicates CO2-induced warming and the second term indicates warming due to the net impact of other human-induced climate drivers such as methane, nitrous oxide or aerosols.
The variables in this equation (which depend on human activity) are as follows: is the average rate of CO2 emissions over this time-period from geological sources (such as fossil fuel combustion and cement production, minus any engineered CO2 removed to geological storage). is the corresponding average rate of CO2 emissions from land-use change, agriculture and forestry minus CO2 removed by active interventions such as afforestation and nature-based solutions: it does not include CO2 uptake by the biosphere that occurs as a result of past CO2 emissions due to natural processes such as CO2 fertilisation. is cumulative CO2 emissions since pre-industrial times up to the middle of this time-period. is the change in, and is the average, net non-CO2 radiative forcing over this time-period. The coefficients in this equation (which are approximately constant) are as follows: is the Transient Climate Response to Emissions, about 0.45 °C per TtCO2 (trillion tonnes of CO2); is the Transient Climate Response to Forcing, about 0.49 Watts per m2 per TtCO2; is the fractional Rate of Adjustment to Constant Forcing, which is about 3% per decade; and is the fractional Rate of Forcing Decline under Zero CO2 Emissions, also about 3% per decade. The fact that means that reducing net CO2 emissions, , to zero would stop CO2 emissions from causing any additional global warming, although warming caused by past CO2 emissions would still persist. The second term shows that net non-CO2 radiative forcing needs to decline at a rate to stop non-CO2 climate pollutants causing additional global warming: hence the SR1.5 statement above. Although often neglected (because it is approximately balanced by the term), the term is important. It is the "passive" uptake of CO2 by the biosphere and oceans that would continue for decades even if all human activity were to cease. This passive uptake, which is not classified as a directly human-caused removal by the IPCC, [5] draws atmospheric CO2 concentrations down (middle right panel of the figure) just fast enough to stop any further global surface warming under net zero CO2 emissions. Hence net zero does not refer to a stable climate equilibrium state, but a dynamic balance between the ongoing adjustment of the global carbon cycle and ocean heat content. Although global average surface temperatures would stop rising, other aspects of the climate system, such as sea level, would continue to change for centuries after net zero emissions is achieved. The size of the term (approximately one quarter of current emissions after net zero is achieved in a 1.5-2 °C scenario) demonstrates the importance of protecting natural carbon sinks in a warming climate. |
Clayoquot ( talk | contribs) 23:30, 9 September 2023 (UTC)
References
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Should we add a short description? I hesitate to set one up and am mindful of long discussions like what we had on the talk page of sustainable energy. Or maybe it's easier than I am thinking. EMsmile ( talk) 21:13, 23 August 2023 (UTC)
The result of the move request was: moved. ( closed by non-admin page mover) EggRoll97 ( talk) 17:49, 5 September 2023 (UTC)
Net zero → Net zero emissions – Following from discussion above, the current title is just a mathematical term that does not directly communicate that the article is about climate change. The proposed title would provide natural disambiguation, as well as sounding less slogan-y. {{u| Sdkb}} talk 16:07, 29 August 2023 (UTC)
it's crucial to normalize that term and concept in order for the energy transition to be successfulOur goal on Wikipedia is not to make the energy transition successful. {{u| Sdkb}} talk 14:26, 31 August 2023 (UTC)
In paragraph 2: "Country-level net zero targets now cover 92% of global GDP, 88% of emissions and 89% of the world population"
In paragraph 3: "While 61% of global carbon dioxide emissions are covered by some sort of net zero target"
These seem to be at odds (88% of emissions and 61% of carbon dioxide emissions). What's the reason for this difference and can this be briefly explained? Markmuetz ( talk) 09:14, 12 September 2023 (UTC)
I copied the following post from my talk page as it would benefit from input from more people. Clayoquot ( talk | contribs) 17:22, 15 September 2023 (UTC)
Hello, I just saw your reply to my comment on the talk page for Net zero emissions saying "Adding “CO2” or “carbon “ to the title would not be accurate. Limiting climate change requires net zero emissions of all greenhouse gases...". That part of the discussion was closed so I just thought I'd explain here that this is not the case. See e.g. https://www.oxfordmartin.ox.ac.uk/news/2018-news-climate-pollutants-gwp/, https://www.nature.com/articles/s41612-018-0026-8. Pagw ( talk) 08:00, 12 September 2023 (UTC)
Just a heads-up to save embarassment: a report by issued this week by Civitas, a London think tank, has been cited heavily by Conservative-aligned media in the UK. Serious errors in methodology have been identified in the report (for example, confusing megawatts with megawatt-hours, billions with trillions) so neither it nor the media that reported it should be considered a reliable source. [1] -- 𝕁𝕄𝔽 ( talk) 16:12, 29 September 2023 (UTC)
References
𝕁𝕄𝔽 ( talk) 16:12, 29 September 2023 (UTC)
I'm wanting to add the UN's minimum requirements for net-zero pledges within their "race to zero" campaign, termed "starting line criteria". However, this article is not specific solely to the U.N. criteria, even if leaning heavily on it (or so it appears).
If the minimum requirements for "race to zero" are added, as well as what percent of orgs are meeting/not meeting them, where would that be best placed within the article? Pyrrho the Skipper ( talk) 02:02, 6 November 2023 (UTC)
For anyone watching this page, could you please have a look at the
low-carbon economy article as well, and check if the two articles interlink well? Do they duplicate some content? Are the methods for getting to a
low-carbon economy the same as those to get to
net zero emissions? Is
net zero emissions really just the "more extreme" / "more ideal" case compared to
low-carbon economy? And how do we define "low"? See also talk page there. For example, I have written there in the lead this sentence, do you agree?: An even more ambitious target than low-carbon economies are zero-carbon economies with
net zero emissions. An example are
zero-carbon cities.
EMsmile (
talk) 09:15, 12 January 2024 (UTC)