But in the past year and a half, a body of evidence has been growing showing that the net effect will be warming. This is based on finer resolution computer models and advanced cloud microphysics.
I think this is generally fair: the available satellite data in particular have shown that clouds seem to act in a way that coincides with higher climate sensitivity.
The fusion of satellite data with climate models has been vital for this.
Previous IPCC reports tended to assume that clouds would have a neutral impact because the warming and cooling feedbacks would cancel each other out.
"Assume" is ungenerous - this was based on calculations using physics and the available observations, e.g. in 2007 they looked at how climate model clouds affected their climate sensitivity and talked about a "very large inter-model spread", i.e. you could get net warming or cooling, and we didn't have the information to rule out either.
https://archive.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-6-2-3.html
He said climate sensitivity above 5C would reduce the scope for human action to reduce the worst impacts of global heating. “We would have no more space for a soft landing of 1.5C [above preindustrial levels]. The best we could aim for is 2C,” he said.
This is a fair interpretation of the consequences: climate sensitivity of 5 C would make it almost impossible to achieve the stated temperature targets.
But there is still plenty of evidence for climate sensitivity being in the historically likely 1.5--4.5 C range, so this should be kept in mind.
the EU’s Community Earth System Model
http://www.cesm.ucar.edu/models/cesm2/ The Community Earth System Model is from US institutions, but it's accurate to say that it's from "leading research bodies" and has a high climate sensitivity.
Without carbon dioxide, all life on Earth would die.
This is ridiculous alarmism and irrelevant.
No one proposes removing all carbon dioxide from the atmosphere. It's just that with more CO2 in the atmosphere, Earth gets hotter and there are consequences of that.
It has never been shown that human emissions of carbon dioxide drive global warming.
Among other evidence, we have directly measured the amount of heating caused by CO2, using instruments pointed at the sky: https://www.nature.com/articles/nature14240 We know the CO2 rise is due to human activity, and this heating is sufficient to explain the observed warming.
Climate change is normal and continual.
Plimer's argument is that "climate change is normal and continual" therefore we can't or shouldn't do anything about the current climate change that's being caused by humans.
This is a bit like arguing that radiation is normal and continual, so if there was a risk of someone using nuclear weapons on your city then you shouldn't try to do anything about that either.
The role of the sun and clouds was not considered important by modelle
This is false, and it's just as false as the last time Plimer claimed this.
Solar activity and clouds are included in climate models. Here's a paper from 2006 talking about how clouds are the largest source of uncertainty in the amount of future global warming: https://journals.ametsoc.org/doi/full/10.1175/JCLI3799.1
Modellers assume carbon dioxide drives climate change.
This is false.
The models include quantum physics and the transfer of heat and radiation according to the laws of physics. They also include things like changing solar activity. That CO2 is the single largest cause of CO2 is an output of the calculations.
If they have failed across the past 30 years when we can compare models with measurements, there is little chance that the climate projections across the next 50 years will be more successful.
The models projected warming, with faster warming at the northern high latitudes. This page includes studies showing that Plimer's statements are inaccurate: https://www.carbonbrief.org/analysis-how-well-have-climate-models-projected-global-warming
In our lifetime, there has been no correlation between carbon dioxide emissions and temperature
This is false.
Our total emissions correlate strongly with temperature, just as expected.
The CDIAC global emissions data are only available until the end of 2014, but the total emissions correlate with global temperature. Over the last 50 years of the datasets the correlation coefficient is 0.93 (where 0 means no correlation and 1 means perfect correlation).
Our bodies contain carbon compounds. If we were so passionately concerned about our carbon footprint, then the best thing to do is to expire.
This is false. The natural carbon cycle keeps atmospheric CO2 amounts approximately in balance.
The changes in atmospheric CO2 are almost entirely due to releasing trapped carbon into the air. The single biggest contributor is digging up carbon that's trapped in fossil fuels and then burning them to release the CO2. A secondary one is releasing carbon trapped in things like forests and peat.
Carbon dioxide is a non-condensable atmospheric gas like nitrogen and oxygen
This is why it is more important than water vapour in forcing the climate to change.
If you add a lot of water vapour to the air, it rains out in hours to days, before it can trap enough heat to warm things up. When we burn fossil fuels, the amount of CO2 in the air will remain higher for at least 100 years.
it sticks around for long enough to drive long-term changes in the climate.
In the past, warming has never been a threat to life on Earth. Why should it be now?
There are plenty of studies showing mass extinction events during past warming. Like during the Paleocene-Eocene Thermal Maximum, where warming was slower than today. The warming was eventually larger than we've seen so far, but it's up to our policy choices as to whether we want to make things hotter than that extinction event or not. https://royalsocietypublishing.org/doi/full/10.1098/rspb.2017.1771 https://science.sciencemag.org/content/314/5806/1770 https://pubs.geoscienceworld.org/gsa/geology/article-abstract/43/5/443/131872
But each serial adjustment has tended to make the early years colder, which increases the warming trend. That’s wildly i
While this says that adjustments increase the total warming, they actually decrease it since the 1800s. https://www.carbonbrief.org/explainer-how-data-adjustments-affect-global-temperature-records
This runs afoul of basic physics.
Sure, over ice the surface is limited in how much it can warm.
Satellite data and buoys confirm that the Arctic is warming and that the data records needed updating. Boisvert et al.: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015GL063775 Susskind et al.: https://iopscience.iop.org/article/10.1088/1748-9326/aafd4e/pdf Dodd et al.: https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-14-00250.1
there’s plenty of ice over much of the Arctic Ocean. Now, for example, when the sea ice is nearing its annual minimum, it still extends part way down Greenland’s east coast. A
There's still about 5 million sq km of ocean where >15 % is ice covered, but that's down by ~3 million sq km (4 Texases, if you will). Even if there's still ice near Greenland.
by replacing satellite data with drifting buoys and temperatures in ships’ water intake.
This isn't what happened. Satellite data was not replaced, it was never there in the first place.
Independent satellite data confirmed that the new corrections are solid: https://advances.sciencemag.org/content/3/1/e1601207
The buoy temperatures, which are measured by precise electronic thermistors, were adjusted upwards to match the questionable ship data. Given that the buoy network became more extensive during the pause, that’s guaranteed to put some artificial warming in the data.
The direction of this adjustment does not affect the trends. This has been repeatedly checked and is well known. While the article says "that's guaranteed to put some artificial warming in the data", it's actually guaranteed not to do that. Because mathematics.
a half-degree from natural causes in the first half of the 20th century, before there was an increase in industrial carbon dioxide that was enough to produce it, and another half-degree in the last quarter of the century.
The earlier warming (~0.3--0.4 C) is about a third to a half of the warming since the 1970s (0.8--0.9 C). They are not comparable, and selecting "the last quarter" of the 20th century to ignore the warming since 2000 misleads readers.
Secondly, human activity was sufficient to cause warming in the first half of the 20th century.
since 1979 to the most reliable observations — those made by satellites and weather balloons over the vast tropics.
These are not the "most reliable" observations. They have the largest issues with lack of independent data to check against, and different groups come up with temperature trends that are far more different than the surface temperature records.
the ongoing rise in sea level that began with the end of the ice age continues with no great increase in magnitude.
It misleads readers not to mention the research suggesting accelerated global warming.
While the authors may think a 50--100 % acceleration of sea level rise is "no great increase", readers may misunderstand this. https://www.nature.com/articles/s41558-019-0531-8
there has been no systematic increase in the frequency of extreme weather events,
It's not clear how you judge "systematic increase in the frequency of extreme weather".
Since the 2013 UN IPCC report, we have new data and analysis showing increases in extreme heat and precipitation in many areas due to human-caused global warming. It is misleading not to mention this.
A quick search would show him that whenever in the past there was an explosion of plant life, the carbon dioxide content was far higher than at present.
The last time carbon dioxide levels were as high as we're on course for, sea levels were 25-40 metres higher. https://science.sciencemag.org/content/326/5958/1394.abstract
The homes of billions of people would be under this sea level. This is projected to take a long time, but even with relatively low emissions we expect tens to hundreds of millions of people's homes to be flood risks due to rising seas this century. And annual flooding costs of trillions of dollars without heavy investment in flood defences or abandoning cities: https://iopscience.iop.org/article/10.1088/1748-9326/aacc76
If you think that potentially causing hundreds of millions of refugees and trillions of dollars in damages is fine because some plants did well in the same conditions millions of years ago when humans weren't around, then you could support this article.
add to emissions because coal-fired electricity needs to be on standby for when there is no wind or sunshine.
Baseless and, where in regions where this has been studied, false.
For example, in Illinois: https://pubs.acs.org/doi/abs/10.1021/es2038432 And this ignores more efficient ways of reducing backup emissions, such as energy storage like batteries.
Renewables such as wind turbines are environmentally disastrous because they pollute a huge land area, slice and dice birds and bats, kill insects that are bird food, create health problems for humans who live within kilometres of them, leave toxins around the turbine site and despoil the landscape.
There is no comparison here with the alternatives. For example, the claimed wind turbine health damages, for which the author shows evidence of zero deaths, should be compared with the millions of deaths that the World Health Organisation links to pollution every year, much of which is from fossil fuels. https://jamanetwork.com/journals/jama/article-abstract/1860459
The amount of energy used to construct solar and wind facilities is greater than they produce in their working lives.
This is false.
The average working wind farm that has been studied produces about 20 times more energy than was used to make them. https://www.sciencedirect.com/science/article/pii/S096014810900055X Some wind farms are better, some are worse. Solar too produces more energy than was used to make the solar farm.
We have also been told the problem is DEFINITELY NOT a billions-year-old planet running through cycles where the temperature might fluctuate a bit. Oh, no, that could never be it — so stop saying that could be, you Denier.
This entire article's "proof" is just saying that "higher CO2 happened before humans, therefore humans can't cause higher CO2".
Here are logically identical arguments: "England scored goals before Harry Kane, so Harry Kane can't score goals" Or in American English: "The New England Patriots scored touchdowns before Rob Gronkowski, so Rob Gronkowski can't score touchdowns" Or more simply: "Fires happened before humans, so humans can't cause fires".
So if you agree with this article's logic and that humans aren't causing CO2 to rise, you also have to believe that Harry Kane and Rob Gronkowski never scored anything and could never score anything, and that no fire has been caused by a human ever.
Human cause global warming, goals by Harry Kane, touchdowns by Rob Gronkowski and fires set by people are all in the same boat. We have enormous evidence that that they exist.
From 1970 until 1998 there was a warming period that raised temperatures by about 0.7 F that helped spawn the global warming alarmist movement. However, since 1998, little warming has occurred while carbon dioxide emissions continue to increase.
Warming ratefrom 1970--1998: +0.15 C/decade, 95 % confidence interval +/- 0.06 C/decade. Warming rate from 1998--2018: +0.18 C/decade, 95 % confidence interval +/- 0.09 C/decade. (calculated with Berkeley Earth).
Odds are that warming after 1998 was faster than warming since 1998. Anyone who looks into the data and has basic analysis skills can see this, so they would not even try to imply that 1970-1998 warming was faster than post-1998 warming.
The whole article uses tricks like this to invert reality, and will leave readers deeply deceived.
Of course climate change is real, climate has been changing for all of Earth’s history”
And if you think that this somehow means that current global warming ain't caused by us, I guess you agree with this:
Barcelona scored goals all through their history, even before Lionel Messi was born! Therefore Lionel Messi can't score goals.
(or for American readers: the Rams scored touchdowns all through their history even before they signed Todd Gurley. Therefore Todd Gurley can't score touchdowns)
Today climate scientists are obsessed with the level of carbon dioxide in the atmosphere, a very very small part of the overall picture. Carbon dioxide is a trace gas.”
When the author of this is willing to inject such a "trace amount" of ebola or ricin into their own body I'll believe that they were being serious with this argument.
: “But what is nature’s most abundant greenhouse gas? Water vapour. It’s not carbon dioxide, it’s not methane… Scientists estimate that somewhere between 75% and 90% of Earth greenhouse effect is caused by water vapour in clouds.”
This calculation estimates each fraction now. If you took the CO2 out and we lost 20 % of the greenhouse effect, Earth would cool down and lots of the vapour would rain out. The amount of water vapour responds to temperature and circulation, nowadays CO2 is the driver.
“So it’s clear now we’re not seeing dangerous global warming, and the climate models are wrong.”
We have done a bunch of comparisons with models and observations. The surface observations are more reliable because there are so many of them, and satellite infrared (think Predator vision) backs them up.
We checked from the 1860s to today and it's remarkable how well the observed warming matches the modelled warming.
https://www.nature.com/articles/nclimate3066 http://advances.sciencemag.org/content/3/1/e1601207
“If we double atmospheric carbon dioxide[…] we’d only raise global surface temperatures by about a degree Celsius.”
More like 3, but only being 200 % wrong is pretty good by the standards of this article.
All of the climate models make an assumption, they all assume a positive feedback from water vapor.”
Physics says that a warmer atmosphere can hold more water vapour. Satellites have measured the increase just as calculated. The positive water vapour feedback is measured reality.
If anything, the Sun has cooled in recent decades. That was reported in 2007: https://royalsocietypublishing.org/doi/full/10.1098/rspa.2007.1880 And new satellite data says it's stayed cooler. https://skepticalscience.com/solar-activity-sunspots-global-warming.htm
22’25: “Greenland is melting a little bit at the edges and getting thicker in the center, but overall the ice is perfectly rock solid, very little change.”
This is false. Greenland lost 2+ trillion tonnes of ice since 2002. http://polarportal.dk/en/greenland/mass-and-height-change/ http://imbie.org/imbie-2012/results/ http://science.sciencemag.org/content/338/6111/1183 And others.
Do we really believe that one bellowing fan in a crowd of 85,000 at the MCG can completely change the course of a game?
Firstly, about 100% of the increase is caused by human activity, because nature is otherwise very close to balanced. That's why atmospheric carbon dioxide is now almost a third higher than any level found in old trapped air in million year old ice cores.
The argument here is that something small doesn't matter. Following its logic, then it must be safe to eat around 28 g (1 Oz) of hydrogen cyanide. Even though research has found that this is enough to kill dozens of people, the article's logic says that there is no way something small can cause harm so eating hydrogen cyanide is fine.
Carbon dioxide is a trace gas in the atmosphere.
This paragraph is also nonsense because carbon dioxide heating has been directly measured. Satellite data was reported in 2001: https://doi.org/10.1038/35066553 And surface data in 2015: https://doi.org/10.1038/nature14240
The extra heating we've caused through carbon dioxide is enough to charge more than 700,000 DeLorean's flux capacitors every second. Or blowing up about 10 Trinity test nukes every second.
there is no relationship between temperature and carbon dioxide emissions by humans
https://doi.org/10.1088/1748-9326/11/5/055006 It's expected that cumulative human emissions and temperature will correlate.
They do. Since 1970 the correlation is extremely strong: almost 90 % of all temperature change correlates with human emissions. About 0.2 % correlates with solar activity, and even that is nonsense because temperatures went up while we measured the Sun getting cooler.
Climate projections also assume that planet Earth is not dynamic
This is nonsense. The models assume that physics works and just implement equations in a way that computers can munch through them.
This makes them imperfect, but this shows complete cluelessness about models or physics.
clouds, back-radiation and the sun were trivial.
This was not assumed, but is a result of equations you get from physics.
Here is a 1989 study that talks about how important clouds are: https://doi.org/10.1126/science.245.4917.513 "Back radiation" is included in all climate models and comes from carbon dioxide, among other gases.
The Sun's activity is included in climate models, although it has been generally cooling if anything over the last 40+ years.
it was assumed carbon dioxide
It was not assumed, this is calculated using equations based on physics.
More than 100 climate models over the past 30 years did not predict what actually happened
Climate model projections from decades ago accurately predicted (1) global warming would happen (2) it would happen faster at high latitudes (3) the Hadley Cell circulati would expand poleward (4) the stratosphere would cool, (5) Arctic sea ice would retreat, (6) convective cloud tops in the tropics would get higher.
These changes have all now been measured. For example, this 1988 study discusses rising convective cloud tops: https://doi.org/10.1175/1520-0469(1988)0451397:CFPIAG2.0.CO;2 And this 2016 study shows it was measured with satellites: https://doi.org/10.1038/nature18273
Just 1.25 per cent of the carbon dioxide in the atmosphere-ocean system has been released by humans in the past 250 years.
About 100 % of the increase in atmospheric carbon dioxide is due to humans. This is easy to show since 1980 using publicly available measurements. Nature emits and absorbs lots, but the net natural contribution over decades is close to zero.
ad author Fischer said that without serious reduction in carbon dioxide emissions, there is "very little margin for error to meet the Paris targets.”
This is a fair summary of the necessary policy response to have a good chance of expecting we could hit the Paris targets.
It also avoids making a value judgment on the Paris Agreement and the scientists stick to technical issues.
Human-inflicted climate change is caused by the burning of fossil fuels such as coal, oil and gas, which release heat-trapping greenhouse gases such as carbon dioxide and methane into the the atmosphere.
This is a fair statement of the scientific understanding. I applaud the author for sticking to credible scientific findings rather than opinions from bloggers or PR sheets produced by political think tanks.
"we cannot comment on how far in the future these changes will occur."
This is an important caveat. Meissner phrases it well and Rice deciding to include it was a good choice.
The changes we see today are much faster than anything encountered in Earth’s history. In terms of rate of change, we are in uncharted waters,” said stud
This is the sentence I have problems with. The study covers 3-4 million years of data, not all of "Earth's history". And as I understand it, paleoclimate proxies give temperature estimates that are often an average over a decade or longer. It makes comparison difficult and I don't see anything in the paper that shows they have sufficient high resolution data to support this general statement.