climate change

That is not necessarily true.  Take the hottest day on record in the UK, 19th July last year at Coningsby. It is well known that there is an issue with the weather station location at Coningsby (next to an active runway). This never used to be an issue when we used the old mercury thermometers as they were slow to respond, but now they use electronic thermometers that respond almost immediately to changes in temp. So on the day the record was set the temp suddenly jumped to the new record and then just as fast fell back - now what could have caused a thermometer next to an active runway record a spike in temperature?.

So yes, we do have new, more accurate equipment - does that necessarily give us an accurate reading though?

Average global temperatures have steadily risen during the 20th century – the graph of increasing temperature is an image frequently used to illustrate man-made climate change. But the graph does not climb steadily: a number of dips and rises occur over the century.

One of these, late in 1945, is more pronounced than the others. The cause of the 1945 dip has so far remained a mystery, something highlighted by people who doubt that climate change is caused by human fossil-fuel burning. They say it is proof that burning fossil fuels cannot explain changes in the climate during the 20th century, given that fossil fuels were being burnt throughout.

That objection may be laid to rest with a study published today in Nature. According to David Thompson of Colorado State University, US, and colleagues it is all down to buckets and human error.

The researchers took a detailed look at the international temperature dataset used by most contemporary climate studies. They first filtered out the effects of natural climate events which are known to cause variations in temperature, such as El Niño events.

In the filtered temperature record, dips were even more pronounced. Each one corresponded to a large volcanic eruption, except for the largest, in 1945. Volcanic eruptions spew large amounts of gases and particles into the atmosphere which block solar radiation and therefore cool the planet.
Human “error”

The global temperature graph is a combination of temperatures taken on land and at sea. When the researchers looked at the land measurements only they saw no dip in 1945. Records taken at sea, however, do show the dip. This suggests that it may be an artefact of how such measurements were taken during the second world war.



Prior to the war, UK and US fleets had contributed roughly equally to the global temperature record. From 1942 to 1945, UK ships, previously an important gatherer of sea water temperatures, were mobilised on the front and contributed just 5% of measurements. Measurements taken from US ships made up 80%.



The key, then, is how each nation took its measurements. UK ships tended to throw a bucket overboard and lift it on deck to take the water’s temperature. US ships by and large would sample water drawn into the engine room before it was used to cool the machinery.

CO2 also causes cooling via photosynthesis. That is a scientific fact. That's why rural areas are significantly cooler than urban areas (up to 5C cooler). 

I wasn't aiming my response at you no. But that man made global warming is a real phenomenon is taken as proven by most climate scientists. What this is likely to mean if allowed to continue is where the differences come in because we are then into the realm of scientific prediction rather than demonstrable facts. But proven facts include a doubling of CO2 in the atmosphere since pre-industrial times. A proven fact is that CO2 is a greenhouse gas and the more of it there is in an atmosphere the warmer it will be. And a proven fact is that natural production of CO2 in this period has not markedly increased but man made production of it has rocketed. Therefore the CO2 that is causing the warming is being put there by us. Ie the warming is man made. No truly reputable climate scientist even begins to reject these basic facts. To do so requires some measure of scientific evidence, with the full expectation that any such source will be looked into by those of us who are aware of the basic science as I have outlined it, to see what the evidence is and how reliable the source is, and what other climatologists have to say about it. But at least any such debate will revolve around the science.

So it does have a cooling effect then Einstein.