COP21 website sets out to disprove sceptical arguments

Global warming stopped in 1998 – since then, temperatures have barely risen.

This claim is based on the Hadley Center report which showed a rise in average temperature of 0.02°C per decade between 1998 and 2008. It has since been widely publicized by climate-change sceptics and wrongly interpreted as a sign that global warming has stopped. But this set of statistics did not include the Arctic, where temperatures have risen significantly in recent years.

This is incorrect, summer minimum has been stable for the last decade on average.

The 21st century has seen the largest number of temperature records broken: 2014 is the hottest year to date since 1850, soon to be overtaken by 2015.

Global warming can be explained by variation in solar activity.

Temperature fluctuations from one year to the next may be linked to changes in solar activity, which varies following a cycle of around eleven years.

However, the amount of solar energy released varies by no more than 0.1%. As Jean Jouzel, Vice-Chair of the IPCC Working Group I, explains, “If the sun governed global warming, the entire atmospheric column would be affected. Yet we are experiencing a warming of the lower layers and a cooling of the stratosphere. This clearly indicates the role played by the worsening greenhouse effect.”

This is blatantly misleading. The sun increased in strength markedly to the peak in the 1950’s and stayed very active until 2003. The cyclic variation is not relevant to this longer term secular rise in activity, now ended.

There is a major element of uncertainty in the calculations that are used to demonstrate global warming / Climate models are not sufficiently accurate.

Climate models are predictions and as such cannot be perfect. Nevertheless, over the years, scientists have fine-tuned them to gain a fairly accurate picture.
The relevance of these models has also been tested on past climate patterns. For if they are borne out by past events, then they are the right way to predict future climate patterns.

As a result, the models used are largely reliable, with a slight discrepancy between predictions and observations . The uncertainty in these models is linked to unpredictable events such as volcanic eruptions or solar activity. But in spite of these intermittent events, long-term climate developments closely match the predictions made using climate models.

A “slight discrepancy”? They’re having a laugh. See plot below.

The IPCC scientists are paid by governments, which leads to a conflict of interests.

In reality, the IPCC co-authors are not paid at all. The organization has only 30 permanent staff, compared with 831 voluntary authors (selected from among 3000 candidates). These volunteers must devote the equivalent of four to five months of work to the report, in addition to their own research.

It is therefore work that relies on the goodwill of the scientific community. Moreover, the authors come from all over the world and are often replaced (69% turnover of authors from the 4th to the 5th report) to promote the exchange of opinions and new ideas.

Misdirection. All these scientists receive their research funding through organisations and institutions which have entrenched positions on climate change.

Many eminent scientists are climate-change sceptics; the existence of global warming is therefore a subject of debate within the scientific community.

There is no longer a debate on the existence of global warming, at least not in the scientific community.

Misdirection. The issue is not whether there has been warming, but whether it is human caused and to what degree.

There is a broad consensus among professionals: 90% consider that the rise in global temperatures is an alarming, proven fact, while 82% agree that global warming is strongly linked to human activity.

The word ‘alarming’ has no provenance here. It is not used in IPCC reports. Again, the issue is not warming, or some degree of human influence, but the magnitude.

Global warming is a natural phenomenon that has already taken place.

The climate is a complex model and varies due to many different parameters. Solar activity, eruptions and sea currents have major impacts in the short term, and even in the medium and long term.

However, today human activity is the prevailing force in global warming, which was never previously the case.

Asserting things in bold typeface does not elevate these assertions to the status of ‘disproving’ sceptical arguments.

Global warming also has positive aspects (warmer winters, etc.).

It is true that a milder winter has short-term benefits, such as lower energy consumption.

However, in the long term, there are many negative aspects to this phenomenon. A succession of mild winters would lastingly affect the quality of cropland by lowering the water tables that supply it, for example. Warmer winters may also disrupt whole ecosystems or foster the spread of diseases (as the cold kills more insects, which are disease vectors).

Where were these people in 2010? or in the Eastern US last winter? Warmer is generally wetter in any case.