However, in contrast to these climate phases, the increase of three-quarters of a degree centigrade (0.74°C) in average global temperatures that we have seen over the last century is larger than can be accounted for by natural factors alone.This is a lie or, at best, extremely disingenuous. The Medieval Climate Optimum (one of the "climate phases" this quote refers to) featured higher global temperatures that we now have.
"It has been alleged that the increased level of carbon dioxide in the atmosphere is due to emissions from volcanoes, but these account for less than one per cent of the emissions due to human activities." That's horseshit, too. "Volcanoes"? There are plenty of natural sources besides volcanoes; human factors account for only three percent of atmospheric carbon dioxide. The "one percent" figure is a lie wrapped in a bit of truth; by mentioning only "volcanoes" as natural sources of CO2 it allows them to make a true statement. But 97% of the CO2 in the atmosphere comes from natural sources.
Before industrialization carbon dioxide made up about 0.03 per cent of the atmosphere or 280ppm (parts per million). Today, due to human influence it is about 380ppm. Even these tiny quantities have resulted in an increase in global temperatures of 0.75ºCIt is said that figures never lie but liars figure, and that quote should be next to that in Bartlett as an example.
280 ppm is 0.03% of the atmosphere. How much is 380 ppm?
And we are meant to believe that a change of 0.01% of the atmosphere is enough to cause "record global warming"? When 95% of the greenhouse effect is due to water vapor?
...carbon dioxide from human sources is almost certainly responsible for most of the warming over the last 50 years.The only problem with that statement is that "the last 50 years" is 1957 to present. Most of the 0.75°C warming they cite repeatedly through all this BS occurred before 1940, which is before most of the increase of CO2. Oh well.
Some have argued that climate change, as a result of human activities, isn't happening because early measurements taken from satellites and weather balloons seemed to show that virtually no warming was happening in the troposphere. However, this has been found to be due to errors in the data. Satellites were found, for example, to be slowing and dropping in orbit slightly, leading to inconsistencies in their measurements. Variations between the instruments onboard different satellites also led to discrepancies a problem that has also been found with weather balloons. Furthermore, a mathematical error in one of the original analyses of satellite data meant that it showed less warming in the troposphere. However, once adjustments are made to take account of these and other issues, the warming in the troposphere is shown to be broadly consistent with the temperature trends we see at the earth's surface.That statement is filled with more lies, twisted statements, and half-truths than anything they've said yet.
In addition, the lower stratosphere has been shown to be cooling and this corresponds with our understanding of what effect global warming should have on this part of the atmosphere. However, some of this cooling is not related to increased levels of greenhouse gases but due to a different impact that humans have had on the atmosphere the depletion of the ozone layer. Ozone warms the stratosphere by trapping incoming energy from the sun. This reduction of ozone also has knock on' effects on other parts of the atmosphere, underlining the importance of taking all factors into account when looking at what is happening to our climate.
a) The satellite orbit showed false warming, not cooling.
b) Data from the ground weather stations have been demonstrated to be faulty.
c) I have discussed the ozone issue raised here at length elswhere on Atomic Fungus.
Modern climate models have become increasingly accurate in reproducing how the real climate 'works'. They are based on our understanding of basic scientific principles, observations of the climate and our understanding of how it functions.Computer models can't predict the weather next week, and if you put real climate data into the computer models they cannot reproduce actual climate changes such as the Little Ice Age and the Medieval Climate Optimum.
By creating computer simulations of how different components of the climate system - clouds, the Sun, oceans, the living world, pollutants in the atmosphere and so on - behave and interact, scientists have been able to reproduce the overall course of the climate in the last century. Using this understanding of the climate system, scientists are then able to project what is likely to happen in the future, based on various assumptions about human activities.
It is important to note that computer models cannot exactly predict the future, since there are so many unknowns concerning what might happen. Scientists model a range of future possible climates using different scenarios of what the world will 'look like'. Each scenario makes different assumptions about important factors such as how the world's population may increase, what policies might be introduced to deal with climate change and how much carbon dioxide and other greenhouse gases humans will pump into the atmosphere. The resulting projection of the future climate for each scenario, gives various possibilities for the temperature but within a defined range.
While climate models are now able to reproduce past and present changes in the global climate rather well, they are not, as yet, sufficiently well-developed to project accurately all the detail of the impacts we might see at regional or local levels. They do, however, give us a reliable guide to the direction of future climate change. The reliability also continues to be improved through the use of new techniques and technologies.
Number Watch, which led me to the Royal Society's site in the first place, has this? to say about the validity of computer models. That link explains the problems of computer climate models much more eloquently than I've ever managed. Next.
Changes in the Sun's activity influence the Earth's climate through small but significant variations in its intensity. When it is in a more active' phase as indicated by a greater number of sunspots on its surface it emits more light and heat. While there is evidence of a link between solar activity and some of the warming in the early 20th Century, measurements from satellites show that there has been very little change in underlying solar activity in the last 30 years there is even evidence of a detectable decline and so this cannot account for the recent rises we have seen in global temperatures."Very little chance in underlying solar activity" if you ignore the fact that we just got past a peak in the 40-year solar activity cycle, that is.
The argument that "the sun has nothing to do with global warming" might get a little more traction with me if Mars and Neptune were not experiencing similar warming to that of Earth. Or are the Martians and Neptunians also generating too much carbon dioxide in their SUVs and factories? *sigh*
...observations of clouds and galactic cosmic rays show that, at most, the possible link between cosmic rays and clouds only produces a small effect. Even if cosmic rays were shown to have a more substantial impact, the level of solar activity has changed so little over the last few decades the process could not explain the recent rises in temperature that we have seen.Take a look at the thought process here.
On the one hand, increasing carbon dioxide from 0.03% of the atmosphere to 0.04% is going to have a catastrophic effect on global temperature, and it's all man-made.
On the other hand, "the level of solar activity has changed so little" means that the sun can't possibly have anything to do with global temperature.
This also speaks to the prior entry, now that I think of it; a tiny change in atmospheric carbon dioxide is going to destroy the ecosystem, but a "tiny" change in the sun's output can't possibly have any effect whatsoever. (I put "tiny" in quotes because the magnitude of the sun's well-recorded variation is much greater than the variation between 280 ppm and 380 ppm.)
The point seems to be that these folks believe that the only "small changes" which matter are the ones that are Man's fault. If climate change is due to changes in solar activity, there isn't anything we can possibly do about it, and the entire "science" of climatology suddenly becomes yesterday's news.
Under one of its mid-range estimates(*), the Intergovernmental Panel on Climate Change (IPCC) - the world's leading authority on climate change - has projected a global average temperature increase this century of 2 to 3 ºC. This would mean that the Earth will experience a larger climate change than it has experienced for at least 10,000 years.Sure. In the worst-case scenario. And in another worst-case scenario, the sun could blow up. But that has nothing to do with reality.
The projection they are talking about here is Mann's "Hockey Stick", by the way, which has been discredited. The program used to generate that figure would generate a "hockey stick" graph from random data; it's worthless. It's worse than that: it's a bald-faced lie. Certainly it isn't anything that even approximates science.
* * *
In the end, the Royal Society's answer to The Great Global Warming Swindle--saying that it's "misleading"--is itself an approximate truckload of misdirection, disingenuousness, and outright fabrication.
If this is the best they can do--if they must resort to this in order to convince us--what does it say about the actual science?