Klimaatverandering: binnen grenzen natuurlijke variabiliteit

Ole Humlum.

Onder de titel, ‘Current Global Warming Is Not Outside The Range Of Natural Variations‘, schonk Michael Bastasch voor de ‘Daily Caller’ aandacht aan twee onlangs verschenen rapporten over de staat van het klimaat. Het eerste was van de hand van Ole Humlum, een Noorse sceptische klimatoloog en webmaster van Climate4you: een website met een schat aan informatie over waarnemingen, zoals temperaturen, ijsbedekking van de polen, zeespiegelstijging enz. enz..

Voor de ‘Global Warming Policy Foundation’ (GWPF) schreef hij onlangs het rapport: ‘The World’s First State Of The Climate Survey Based on Observations Only.‘ Het rapport is hier te vinden.

Voorts schonk Bastasch aandacht aan een recent klimaatrapport van de WMO.

Aan de introductie en inleiding van het rapport van Humlum ontleen ik het volgende:

A report on the State of the Climate in 2016 which is based exclusively on observations rather than climate models is published today by the Global Warming Policy Foundation (GWPF).

Compiled by Dr Ole Humlum, Professor of Physical Geography at the University Centre in Svalbard (Norway), the new climate survey is in sharp contrast to the habitual alarmism of other reports that are mainly based on computer modelling and climate predictions.

Among the key findings of the survey are:

• While 2016 was one of the warmest years on record, global temperatures dropped back at the end of the year to levels prior to the strong 2015/16 El Niño. This fact suggests that much of the global 2015–16 temperature peak was caused by a one of the strongest El Niños on record.

• Since 2003, the global temperature estimate based on surface station measurements has consistently drifted away from the satellite-based estimate in a warm direction, and is now about 0.1◦C higher.

• Much of the heat given off during the 2015–16 El Niño appears to have been transported to the polar regions, especially to the Arctic, causing severe weather phenomena and unseasonably high air temperatures.

• Data from tide gauges all over the world suggest an average global sea-level rise of 1–1.5 mm/year, while the satellite-derived record suggests a rise of more than 3 mm/yr. This noticeable difference between the two data sets still has no broadly accepted explanation.

• Arctic and Antarctic sea-ice extents since 1979 have developed in opposite directions, decreasing and increasing, respectively. In the Arctic, a 5.3-year periodic variation is important, while for the Antarctic a cycle of about 4.5 years duration is important. Both these variations reached their minima simultaneously in 2016, which explains the recent minimum in global sea-ice extent.

Deze verklaring biedt dus een alternatief voor de opvattingen van de klimaatalarmisten, die deze vermindering ‘framen’ als een bevestiging van de AGW-hypothese (AGW = ‘Anthropogenic Global Warming). Zie hier.

Prof Humlum said: “There is little doubt that we are living in a warm period. However, there is also little doubt that current climate change is not abnormal and not outside the range of natural variations that might be expected.”

Ongeveer tegelijkertijd verscheen het laatste klimaatrapport van de WMO. Zoals gebruikelijk was dit weer rijkelijk overgoten met klimaatalarmistische saus.

Michael Bastasch:

The Global Warming Policy Foundation’s (GWPF) climate assessment, like the World Meteorological Organization (WMO), noted 2016 was likely the warmest year on record due to an incredibly strong El Niño warming event that boosted tropical ocean temperatures starting in 2015.

That’s about all the GWPF’s report has in common with the WMO’s assessment for 2016, which warns “the influence of human activities on the climate system has become more and more evident.” …

Humlum found that while 2016 was the warmest year on record, it was mostly due to the incredibly strong El Niño. The WMO, on the other hand, claims El Niño only contributed between 0.1 to 0.2 degrees Celsius to 2016’s record 1.1 degree Celsius anomaly.

He argues El Niño was the main driver behind record high temperatures last year because “global air temperatures were essentially back to the level of the years before the recent 2015–16 oceanographic El Niño episode.”

In general, the WMO’s report takes a more ominous tone in general when describing climatic conditions in 2016. WMO reported the “increase in global temperature is consistent with other changes in the climate system.”

“Globally averaged sea-surface temperatures were also the warmest on record; global sea levels continued to rise; and Arctic sea-ice extent was well below average for most of the year,” WMO reported.

“The year was marked by severe droughts that affected agricultural production and left people exposed to food insecurity in southern and eastern Africa and Central America,” WMO reported, also mentioning Hurricane Matthew, heavy flooding in Asia and coral reef bleaching.

Humlum counters that unseasonably high temperatures in the Arctic were driven by El Niño. Heat transported from the tropics to the poles. Both poles saw record-low sea ice levels, but that could also be driven by natural cycles.

“In the Arctic, a 5.3-year periodic variation is important, while for the Antarctic a cycle of about 4.5 years duration is important,” Humlum wrote. “Both these variations reached their minima simultaneously in 2016, which explains the recent minimum in global sea-ice extent.”

Humlum also noted how surface-based temperature datasets have diverged from satellite-based readings since 2003. Surface data shows about 1 degree Celsius more warming than satellites.

Many scientists, however, are worried about what 2017 holds. UK Met office scientists forecast atmospheric carbon dioxide could reach 410 parts per million by May, though those same experts expect 2017 to be cooler than 2016.

“Even without a strong El Niño in 2017, we are seeing other remarkable changes across the planet that are challenging the limits of our understanding of the climate system,” said David Carlson, director of the WMO-funded World Climate Research Program, according to InsideClimate News.

“We are now in truly uncharted territory,” Carlson said.

Aldus Michael Bastasch.

Lees verder hier.

‘Truly uncharted territory’? En er is ons altijd verteld: ‘The science is settled. All scientists agree.’

Voor mijn eerdere bijdragen over klimaat en aanverwante zaken zie hier, hier, hier, hier en hier.