Real Global Temperature Trend, p8 – Major eruption of Mexican Popocatépetl volcano can cause temporary cooling, 1997 Nature study warned

In our series about the ‘Real’ Global Temperature Trend we’ve learned not to exaggerate the climate cooling potential of volcanoes. That is because many volcanoes are of the wrong type, lie on the wrong latitude – or, the vast majority, are simply too small to cause a significant dip in global temperatures.

Webcam image of Popocatépetl explosive eruption of April 3 2016
Continue reading

Real Global Temperature Trend, p7 – ‘Volcanoes did not cool the Earth in the 1980s, so Climate Sensitivity at least 2.1 to 8.9 degrees Celsius’

Even if you assume a low value for the variables of SO2 cooling and the rate of heat uptake by the deep ocean. Yes, that caught our eyes too.

“Studies of these [volcanic eruptions and El Niño] effects using climate models have improved understanding of the climate system and increased confidence in projections of global warming from anthropogenic greenhouse gases” – Alan Robock, Rutgers University in Encyclopedia of Global Environmental Change (2002)

Major volcanic eruptions indicate climate sensitivity might be higher
Continue reading

Real Global Temperature Trend, p6 – THIS is the line you get when you combine ALL (established) temperature measurements

You know about our series by now. We’re investigating the ‘Real Global Temperature Trend‘. That means, as we swim through a turbulent ocean of climate records, we want to maintain a clear view on the horizon – to see where exactly we’re going, and how fast.

To do so the below graph is very helpful. Very helpful for anyone who wants to know what’s going on with the climate. Because before you can establish what exactly should be the height and shape of the climatological trend line (spoiler: that one is higher than this one, do follow our series to understand why) you of course first need to be able to draw a proper statistical trend line.

Global temperature trend line from observed data - 5 datasets
Continue reading

Real Global Temperature Trend, p5 – Climate Sensitivity higher when models include subtropical cloud-decrease feedback

We could say clouds are too complicated for climate science – and ignore them forever. We could also just try to incorporate them in the models. If you do, chance is you’ll find climate sensitivity is underestimated, a very interesting publication in Science from 2012 tells us:

Climate sensitivity cloud feedback: subtropics drier - and hotter?
Continue reading

Real Global Temperature Trend, p4 – If Aerosol Cooling strongly overestimated(?), then Climate Sensitivity is low, says cherry pick study

Several studies suggest global dimming aerosol cooling is not overestimated, but underestimated. But in our quest to uncover ‘The Real Global Temperature Trend‘ – we need to be open for all possibilities – even the bizarrely unsatisfying slap in the face of sometimes encountering ‘possible good news’ (God No!) while again skipping breakfast to read through piles of climate journals, even the low impact ones. The dark corner of the scientific library. We found a picture of a naked scientist once. Today it’s worse:

Continue reading

Real Global Temperature Trend, part 3 – Global Dimming declining, but could still mask 50 percent of CO2 warming(!)

Amidst a storm of climate records here at Bits of Science we’re searching for ‘The Real Global Temperature Trend’. Today is part three of the series – the second episode about ‘Global Dimming‘. Although worldwide aerosol pollution is slowly declining (see the first graph of this article, below), it could still mask about half of the actual global warming temperature trend, a publication in Nature from 2007 suggests – that looked at the 3D temperature effects of the ‘Asian Brown Cloud‘.

Global dimming is declining, this graph shows
Continue reading

New study: Recent drought eastern Mediterranean (Levant, incl. Syria) worst since Middle Ages, but complicated story

Droughts, or rather ‘air subsidence, hence low precipitation and high evaporation’ belong to the subtropics – therefore much of North Africa and the Middle East is covered by (semi) desert. What is a concern though, is possible further drying due to climate change in agriculturally productive areas, such as Egypt’s Nile Delta, the western Sahel and especially the so-called ‘Fertile Crescent‘, encompassing much of Israel, Lebanon, Syria and Iraq.

Mediterranean droughts throughout climate history - ancient Egypt
Continue reading

US climate denial crumbling – Americans that say climate change caused by humans at all-time high

A new Gallup poll shows a couple of very interesting developments. As graphed below the number of Americans that think the witnessed rise in global average temperatures is caused by human pollution has risen to an all-time high, at 65 percent – a jump from 55 last year:

Graph American climate change concern rising
Continue reading