A new study by a team of leading climate scientists suggests that the effect of carbon dioxide this century might be small if not undetectable when compared to natural climate variability.
Global surface temperature is and always has been the key climate parameter. Whatever is happening to the Earth’s climate balance, it must, sooner or later, be reflected in the global annual average temperature, and not just in regional variations. [emphasis, links added]
But therein lies what is to some an inconvenience as the changes in the global temperature this century are open to differing interpretations including the suggestion that increases in anthropogenic greenhouse gas emissions are not needed to explain the changes we have seen in the last 20 years or so.
It’s a conclusion that many would dismiss as coming from climate “skeptics,” or downright deniers.
But what if it’s the view of scientists from two of the world’s leading institutes researching climate change; the University of Oxford and the US National Center for Atmospheric Research? Then it must be taken seriously and not dismissed offhand.
It is important research because it is the trend in the increase of global temperature caused by anthropogenic [human-caused] greenhouse gas emissions that is the most important variable for policymakers considering the scale and timescale of action in the coming decades.
However, this vital parameter is uncertain because recent decades have shown that we are living through a period of considerable natural climate variability.
Thus, a new study published in the Journal of Climate suggests the effect of carbon dioxide this century might be small if not undetectable when compared to natural climate variability.
The researchers contend that recent temperature trends might indicate that there is no detectable increase in global temperature due to greenhouse gas emissions.
While this suggestion is interesting it must be said that the researchers get themselves in a muddle when estimating temperature trends this century.
On the one hand, they acknowledge the existence of the global temperature hiatus between 2000 – 2014, but on the other hand, they do not properly distinguish the effects of the natural El Nino events that have taken place in the past seven years.
This is why they conclude there might have been an acceleration in global temperature increase over this period.
They say that most of the increase is not due to greenhouse gases but to aerosol emission reductions.
The combustion of fossil fuels releases greenhouse gases but it also causes pollution that cools the Earth, offsetting any warming.
This is good news for public health as airborne particles kill several million people a year, but it also accelerates global warming.
They assess that aerosol emissions have contributed to an increase in the rate of anthropogenic warming since 2000 although they have large uncertainty.
When considering estimates of the amount of warming due to aerosol reduction along with natural climate variability, they find a solution with all the post-2000 temperature trends being due to natural variability alone.
They say (p 4283) it’s a credible hypothesis that global temperature changes since 2000 could be “arising largely from internal variability.”
Read more at NZW
I don’t take sides, I actually read source documents. I guess I’m the only one that actually read the linked document, including the author of this blog! (or, they linked to the wrong article??)
Minimal discussion of CO2 and global warming – it’s almost a ‘given’ in the paper without any analysis because that wasn’t the focus. What they were focusing on was effective radiative forcing (ERF) and its increase, which is likely due to the reduction of aerosols dumped into the atmosphere in the last few decades.
No good news here, except the fact that historical environmental laws on aerosols likely contributed to helping some heat escape the atmosphere faster than scientists had thought.
Frankly all Global Warming types should live in Grass or Mud Huts without any Electricity to keep them warm and cook their food after all Hollywood screwballs like Cameron Daiz and Drew Barrymore think the Primative people are better then us moderns time for them to put their money where their mouths are
Just a reminder that the cooling towers in the photo give off water vapor not CO2
Do we know who these leading scientists are?
https://journals.ametsoc.org/view/journals/clim/35/24/JCLI-D-22-0081.1.xml
Ed, thanks for the link. They seem to conclude that the reduction in atmospheric aerosols lets more sunlight reach the surface and the result is more back radiation from greenhouse gas. Am I correct?
Clean air contributes to climate change?
Is carbon dioxide making the earth greener?
Authors of the paper reviewed more than 250 published articles and found that the global greening was due to increased levels of carbon dioxide in the atmosphere. Interestingly, this phenomenon made earth cooler; as vegetation consumed carbon dioxide, it performed evapotranspiration.
-the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants.
Water vapor is termed as a GHG, which HOLDS HEAT IN, so please explain the obvious contradiction above.
The Net is a mass of contradictions as is the the supposed science termed Climatology.
It was predictable that more sunlight would reach the Earth’s surface when aerosols and particulates were reduced . The warmists don’t want to acknowledge any influence other than CO2 and methane. I’ve mentioned this before but I’ll say it again, when all air travel was grounded immediately after 9-11, the Earth’s surface warmed measurably.
Absolutely correct
Going back further than the year 2000 there is more evidence that carbon dioxide has little if any impact on the earth average temperature. One of the most compelling is that 40% of the warming blamed on man occurred between 1910 and 1941 when the carbon dioxide levels were relatively low and raising very slowly.
At no point in human 200 thousand-year existence, has the climate not been actively, naturally changing. Actively warming and cooling within 12°C temperature ranges that dwarf even the failed CO2-driven climate models’ hypochondriacal projections. Shakun et al’s fake graph that imagines an unchanging climate prior to the most recent few decades of warming was commissioned by an American government agency, the National Science Foundation. Shakun himself admits that he used 3 or four different scales in the same graph to make the climate appear to be unchanging prior to the last few decades. Entirely false. Shakun warned whoever decided to use this fake graph to indoctrinate a generation with the climate lie that this was not truthful science. They used it anyway. Here’s the truth about carbon and its atmospheric source CO2. Life on earth is carbon based. All living beings from the simplest single-celled organisms to Homo Sapiens Sapiens (human beings) are composed entirely of little carbon (lipid) sacks of water we call cells. Resulting in carbon being the second most abundant element (18.5%) in living bodies. (Oxygen is the most abundant (65%) from cellular and intercellular water (H2Oxygen). These two elements are over 80% of the mass of elements that compose life. All life dies without CO2. When we consume the high energy “fossil” fuels coal, oil, and gas, we recycle the two most important ingredients of life – CO2 and H2O! Besides making ourselves the best-fed, longest-living, most prosperous human beings that have ever existed, recycling CO2 back to the atmosphere makes the environment greener, stronger, more drought tolerant, and abundant. And it allows us to feed eight billion people easier than to feed 3.5 billion a century ago. It’s hard to imagine government making a bigger, more deadly mistake than this false attack on 85% of the world’s energy. Stupidly and ignorantly imagining they can replace 85% of the world’s energy with inflationary energy that doesn’t work when the sun doesn’t shine and the wind doesn’t blow. If frightening a generation of schoolchildren with this climate lie about CO2 isn’t criminal, it should be.
Well said! It’s time to understand that our government has become increasingly sociopathic in character; it has no conscience. As more climate propaganda is rolled out, government insists on an anti-fossil fuel energy policy, knowing it will punish us economically. Censorship is ok they must decide what is truth! They lie to us hourly and spend money to maintain their power and control. Freedom, liberty and capitalism is too destructive to climate so our government is actively sacrificing the foundation of our nation to “fight climate change”! Their war is against us not climate change.
I agree 100% percent. The climate BS is all political!