Twenty years of two and a half degrees of warming

[ViaCrucis]

The Sun is the culprit behind the modern warming trend.

It isn't. It's anthropogenic.

-CryptoLutheran

 

[Subduction Zone]

Who decided what normal was?

Statistics tell us what is normal.

 

[Goonie]

Statistics tell us what is normal.

Indeed and for most of earths lifespan Earth has been uninhabitable, it's looking like we are returning to the norm.

 

[Ophiolite]

Indeed and for most of earths lifespan Earth has been uninhabitable, it's looking like we are returning to the norm.

Uninhabitable for whom? I take it you are referring to complex, multi-cellular eukaryotes. The Earth has been inhabited since at least 3.3 Ga and possible 3.9 Ga, so roughly 70% - 90% of its existence.

 

[Subduction Zone]

Indeed and for most of earths lifespan Earth has been uninhabitable, it's looking like we are returning to the norm.

I don't think it will be that bad. But a lot of species will go extinct and mankind is likely to suffer quite a bit as well.

 

[Gene2memE]

Who decided what normal was?

Normal, at least in terms of global temperatures, is an average of 30 years of temperature measurements.

The WMO breaks things down nicely:
GCDS_1 WCDMP | WMO

Climatological Normals have long filled two major purposes. Firstly, they form a benchmark or reference against which conditions (especially current or recent conditions) can be assessed, and secondly, they are widely used (implicitly or explicitly) as an indicator of the conditions likely to be experienced in a given location. The Technical Regulations and earlier editions of Guide to Climatological Practices contain a number of explicit definitions, as well as terms which are not formally defined but have a clear meaning. These terms are:

Averages: The mean of monthly values of climatological data (which may be monthly means or totals) over any specified period of time (no specific definition).

Period averages: Averages of climatological data computed for any period of at least ten years starting on 1 January of a year ending with the digit 1 (Technical Regulations).

Normals: Period averages computed for a uniform and relatively long period comprising at least three consecutive ten-year periods (Technical Regulations).

Climatological standard normals: Averages of climatological data computed for the following consecutive periods of 30 years: 1 January 1981 to 31 December 2010, 1 January 1991 to 31 December 2020, etc. (Technical Regulations).​

 

[grasping the after wind]

Normal, at least in terms of global temperatures, is an average of 30 years of temperature measurements.

The WMO breaks things down nicely:
GCDS_1 WCDMP | WMO

Climatological Normals have long filled two major purposes. Firstly, they form a benchmark or reference against which conditions (especially current or recent conditions) can be assessed, and secondly, they are widely used (implicitly or explicitly) as an indicator of the conditions likely to be experienced in a given location. The Technical Regulations and earlier editions of Guide to Climatological Practices contain a number of explicit definitions, as well as terms which are not formally defined but have a clear meaning. These terms are:

Averages: The mean of monthly values of climatological data (which may be monthly means or totals) over any specified period of time (no specific definition).

Period averages: Averages of climatological data computed for any period of at least ten years starting on 1 January of a year ending with the digit 1 (Technical Regulations).

Normals: Period averages computed for a uniform and relatively long period comprising at least three consecutive ten-year periods (Technical Regulations).

Climatological standard normals: Averages of climatological data computed for the following consecutive periods of 30 years: 1 January 1981 to 31 December 2010, 1 January 1991 to 31 December 2020, etc. (Technical Regulations).​

If normal is the average temperature of the last 30 years, then how can this statement below from greatcloudlives have any significance? Or accuracy for that matter? I can't see that the average of the 20 years out of an average of 30 years would be that far off the 30 year average. would the ten remaining years be that much colder?

The world wide temperature has been a steady two and a half degrees above normal for twenty years.

If one waits a year perhaps the world wide temperature for the twenty year period will be much less than two and a half degrees above normal? Normal may well have moved up or down a bit or the twenty year period may have moved down or up a bit. Which might be the case if this year is extremely high or low in global temperature and the year that is removed from the equation was extremely low or high in global temperature. Supposing there is a normal temperature that the global temperature is supposed to be would be much different than just averaging the last 30 years and calling it it normal. Using the 30 year model we will always be close to normal whether the average temperature is boiling hot or ice age cold.

 

[Gene2memE]

If normal is the average temperature of the last 30 years, then how can this statement below from greatcloudlives have any significance?

It doesn't, because he's wrong.

I can't see that the average of the 20 years out of an average of 30 years would be that far off the 30 year average. would the ten remaining years be that much colder?

Look at the past 30 years of climate temperature data. If you just take the 20 years from 1990 to 2009, the average climate anomaly is 0.48 degrees (relative to a 1950 to 1980). If you add the next 10 years, the anomaly is 0.59 degrees (a 23% increase). That's a MASSIVE difference.

If one waits a year perhaps the world wide temperature for the twenty year period will be much less than two and a half degrees above normal? Normal may well have moved up or down a bit or the twenty year period may have moved down or up a bit. Which might be the case if this year is extremely high or low in global temperature and the year that is removed from the equation was extremely low or high in global temperature. Supposing there is a normal temperature that the global temperature is supposed to be would be much different than just averaging the last 30 years and calling it it normal. Using the 30 year model we will always be close to normal whether the average temperature is boiling hot or ice age cold.

That's the point. The data is smoothed over a long period of time to give a realistic average. We then pick a benchmark period (generally 1950 to 1980) to use as a baseline, and measure against this.

So if you exclude a particularly hot year from the data, there's not that much effect. If we take 1998 or 2016 out of a 1990 to 2019 benchmark, then the difference of taking out either of these two very hot years is only 0.014 of a degree to the warming trend (about 2.5% of the warming effect).

Even if 2020 is 2 degrees Celsius above the 1950 to 1980 trend (double the previous warmest year), this will only move the warming trend from 0.596 degrees over 30 years to 0.647. However, 10 years of 2 degrees of warming would move the trend from 0.596 degrees to 1.13 degrees.

 

[Aussie Pete]

Not consistent with the evidence. There's considerable evidence for a greenhouse effect coming from CO2 and other gasses. Just this time it's being released by us and not volcanoes or other natural sources.

Just today there was a report that it's methane that is the worst offender. That was known to some extent, but now the scientific community says that it's methane from the oil, gas and coal industry that it mostly to blame. So the world has been clamouring for CO2 reduction at great expense and for little benefit. Ah science, you've done it again.

 

[Gene2memE]

Just today there was a report that it's methane that is the worst offender. That was known to some extent, but now the scientific community says that it's methane from the oil, gas and coal industry that it mostly to blame. So the world has been clamouring for CO2 reduction at great expense and for little benefit. Ah science, you've done it again.

Can you link to the report?

Methane has been a known greenhouse gas and warming contributor for decades (the first IPCC report from 1990 covers it and its global warming potential, for instance).

Methane has a warming potential about 80 to 100 times that of carbon dioxide. However, its effect is more short term, as methane only has a atmospheric dwell life of somewhere between 9 to 12.5 years (compared to about 200 years for carbon dioxide).

Thus, it will have a warming impact over 100 years of about 25 to 30 times that of carbon dioxide.

However, methane is a lot less common in the atmosphere. Current concentration is about 1900 parts per billion (0.0000019% of the atmosphere), compared to about 400 parts per million for carbon dioxide (0.0004% of the atmosphere).

Thus, there is 2000 times as much carbon dioxide in the atmosphere than methane and it will stay in the atmosphere almost 20 times as long.

This is why CO2 is the primary focus.

 

[Aussie Pete]

Can you link to the report?

Methane has been a known greenhouse gas and warming contributor for decades (the first IPCC report from 1990 covers it and its global warming potential, for instance).

Methane has a warming potential about 80 to 100 times that of carbon dioxide. However, its effect is more short term, as methane only has a atmospheric dwell life of somewhere between 9 to 12.5 years (compared to about 200 years for carbon dioxide).

Thus, it will have a warming impact over 100 years of about 25 to 30 times that of carbon dioxide.

However, methane is a lot less common in the atmosphere. Current concentration is about 1900 parts per billion (0.0000019% of the atmosphere), compared to about 400 parts per million for carbon dioxide (0.0004% of the atmosphere).

Thus, there is 2000 times as much carbon dioxide in the atmosphere than methane and it will stay in the atmosphere almost 20 times as long.

This is why CO2 is the primary focus.

Huge recalculation of methane emissions has a silver lining: 'We can deal with it'

 

[essentialsaltes]

Just today there was a report that it's methane that is the worst offender.

Article doesn't say that.

"And while methane is the second most significant greenhouse gas, contributing about 16 per cent of warming,"

Ah science, you've done it again.

Incrementally increased our knowledge, you bet!

 

[Gene2memE]

Huge recalculation of methane emissions has a silver lining: 'We can deal with it'

So, that report wasn't that "it's methane that is the worst offender" like you stated in post #29. All is does is revise the attribution of where the majority of fossil methane originates from.

According to the study in Nature, previous estimates overstated natural emissions and underestimated human caused emissions:

"anthropogenic fossil CH4 emissions are underestimated by about 38 to 58 teragrams CH4 per year, or about 25 to 40 per cent of recent estimates".​

The study now estimates that 96-99% of fossil methane emissions are human caused, up from the previous estimate of 64-75%.

And fossil methane is only about 30% of total atmospheric methane. So its really only a revision of a minority segment, of a minority segment, of greenhouse gas emissions.

So the world has been clamouring for CO2 reduction at great expense and for little benefit. Ah science, you've done it again.

TOTAL RUBBISH. From the ABC article you linked:

"And while methane is the second most significant greenhouse gas, contributing about 16 per cent of warming, Professor Etheridge emphasised that reducing carbon dioxide emissions is still the greatest priority for tackling long-term climate change."​

This study indicated there's no difference in the estimate of the AMOUNT of methane in the atmosphere, just the SOURCE of one segment of it. ie, the vast majority of fossil atmospheric methane is coming from human activities, not two thirds of it like we previously though.

Sheesh.

 

[Ophiolite]

@Aussie Pete I hope you are well. It is now three days since Gen2MemE and essentialsaltes corrected your misrepresentation/misunderstanding of the relevance of methane. When do you plan to acknowledge your misrepresentation/misunderstanding?

 

[Aussie Pete]

I apologise profusely and I apologise for not apologising sooner.

 

[lordjeff]

Not consistent with the evidence. There's considerable evidence for a greenhouse effect coming from CO2 and other gasses. Just this time it's being released by us and not volcanoes or other natural sources.

Volcanic action is active & accounts for a large portion of what they have measured because that's where the instruments are. The sun is indeed the culprit behind this. Greenhouse gases on a planet type like the Earth can't exude that much effect. Earth has no ceiling unlike it's twin Venus. We also maintain 3 large repositories: the oceans, vegetation, & limestone/calcite. Venus lacks all these. CO2 is indeed a greenhouse gas but CO2 follows warming, not precedes warming. When warming occurs, this facilitates both mechanical & chemical weathering of rocks, in which case limestone can release its CO2.

 

[Gene2memE]

Volcanic action is active & accounts for a large portion of what they have measured because that's where the instruments are.

Not according to the US Geological Survey. They estimate that volcanoes account for about 0.9% of current CO2 emissions and an even smaller proportion of total GHG emissions.

The sun is indeed the culprit behind this. Greenhouse gases on a planet type like the Earth can't exude that much effect.

Given that recent warning is completely decoupled from solar activity, that seems unlikely.

Also given what is known about C02 and other GHGs, they can indeed produce the witnessed warming.

Earth has no ceiling unlike it's twin Venus.

I'm not even sure what this means.
QUOTE]

 

[Shemjaza]

Volcanic action is active & accounts for a large portion of what they have measured because that's where the instruments are. The sun is indeed the culprit behind this. Greenhouse gases on a planet type like the Earth can't exude that much effect. Earth has no ceiling unlike it's twin Venus. We also maintain 3 large repositories: the oceans, vegetation, & limestone/calcite. Venus lacks all these. CO2 is indeed a greenhouse gas but CO2 follows warming, not precedes warming. When warming occurs, this facilitates both mechanical & chemical weathering of rocks, in which case limestone can release its CO2.

Except that isn't true.

"CO2 is indeed a greenhouse gas but CO2 follows warming, not precedes warming"
In particular, this seems to be a contradiction.

 

[lordjeff]

Except that CO2 follows warming is indeed true per some Nobel Laureates. You can never decouple the solar properties from warming or cooling. Geologists estimate some 200 Gigatons of CO2 from volcanos. Volcanos are just powerful little engines. GHGs can't produce more than a couple degrees because we have the 3 large repositories. On Venus its cloud cover keeps its gases below the cloud level. The Earth has changeable sky conditions largely because it has weather. In addition there are several layers of the atmosphere so after a certain residence time some gases are lost to space. By the way I am an earth scientist, geology minor.

 

[lordjeff]

It isn't. It's anthropogenic.

-CryptoLutheran

Afraid not. Sun has complicated cycles. We have complex atmosphere & geology. Unequal distribution of heat. There were always greenhouse/icehouse states in Earth's history-take a course in paleogeology or paleoclimatology. In particular, when the planet was in its primordial state, it was very hot & unliveable (Hadean, Archaen Eras). Very hostile conditions. And most of the ingredients derived from volcanic action above ground, magma movement underground, the eventual arrival of rain, & then bacteria. Mankind is unable to appreciate the depth of previous heat or cold in the long past because are lives are rather short relative to time frames used to describe the Earth's historical geology. No one can tell us what the climate was on say March 1, 545MA no more than they can tell us what happened on June 1, 16,000 BCE.