Archives par mot-clé : Natural Cycles

New Study: Greenhouse Gases May Not Be Causing 21st-Century Warming

by D. Whitehouse, Dec 16, 2022 in ClimateChangeDispatch


A new study by a team of leading climate scientists suggests that the effect of carbon dioxide this century might be small if not undetectable when compared to natural climate variability.

Global surface temperature is and always has been the key climate parameter. Whatever is happening to the Earth’s climate balance, it must, sooner or later, be reflected in the global annual average temperature, and not just in regional variations. [emphasis, links added]

But therein lies what is to some an inconvenience as the changes in the global temperature this century are open to differing interpretations including the suggestion that increases in anthropogenic greenhouse gas emissions are not needed to explain the changes we have seen in the last 20 years or so.

It’s a conclusion that many would dismiss as coming from climate “skeptics,” or downright deniers.

But what if it’s the view of scientists from two of the world’s leading institutes researching climate change; the University of Oxford and the US National Center for Atmospheric Research? Then it must be taken seriously and not dismissed offhand.

It is important research because it is the trend in the increase of global temperature caused by anthropogenic [human-caused] greenhouse gas emissions that is the most important variable for policymakers considering the scale and timescale of action in the coming decades.

However, this vital parameter is uncertain because recent decades have shown that we are living through a period of considerable natural climate variability.

Thus, a new study published in the Journal of Climate suggests the effect of carbon dioxide this century might be small if not undetectable when compared to natural climate variability.

The researchers contend that recent temperature trends might indicate that there is no detectable increase in global temperature due to greenhouse gas emissions.

While this suggestion is interesting it must be said that the researchers get themselves in a muddle when estimating temperature trends this century.

On the one hand, they acknowledge the existence of the global temperature hiatus between 2000 – 2014, but on the other hand, they do not properly distinguish the effects of the natural El Nino eventsthat have taken place in the past seven years.

This is why they conclude there might have been an acceleration in global temperature increase over this period.

They say that most of the increase is not due to greenhouse gases but to aerosol emission reductions.

The combustion of fossil fuels releases greenhouse gases but it also causes pollution that cools the Earth,offsetting any warming.

This is good news for public health as airborne particles kill several million people a year, but it also accelerates global warming.

They assess that aerosol emissions have contributed to an increase in the rate of anthropogenic warming since 2000 although they have large uncertainty.

When considering estimates of the amount of warming due to aerosol reduction along with natural climate variability, they find a solution with all the post-2000 temperature trends being due to natural variability alone.

They say (p 4283) it’s a credible hypothesis that global temperature changes since 2000 could be “arising largely from internal variability.”

Read more at NZW

Also here

NEW STUDY: 23 EXPERTS IN THE FIELDS OF SOLAR PHYSICS AND CLIMATE SCIENCE CONTRADICT THE IPCC — THE SCIENCE IS NOT SETTLED

by Cap Allon, Aug 16, 2021 in Electroverse


A diverse expert panel of global scientists finds blaming climate change mostly on greenhouse gas emissions was premature. Their findings contradict the UN IPCC’s conclusion, which the study shows, is grounded in narrow and incomplete data about the Sun’s total solar irradiance (TSI).

A new scientific review article has just been published on the role of the Sun in climate change over the last 150 years.

It finds that the United Nations’ Intergovernmental Panel on Climate Change (IPCC) may have been premature in their conclusion that recent climate change is mostly caused by human greenhouse gas emissions.

The paper by 23 experts in the fields of solar physics and of climate science from 14 different countries is published in the peer-reviewed journal Research in Astronomy and Astrophysics (RAA).

The paper, which is the most comprehensive to date, carries out an analysis of the 16 most prominent published solar output datasets, including those used by the IPCC.

The researchers compared them to 26 different estimates of Northern Hemisphere temperature trends since the 19th century (sorted into five categories), including the datasets used by the IPCC.

They focused on the Northern Hemisphere since the available data for the early 20th century and earlier is much more limited for the Southern Hemisphere, but their results can be generalized for global temperatures.

Dr. Ronan Connolly, lead author of the study, at the Center for Environmental Research and Earth Sciences (CERES):

“The IPCC is mandated to find a consensus on the causes of climate change. I understand the political usefulness of having a consensus view in that it makes things easier for politicians. However, science doesn’t work by consensus. In fact, science thrives best when scientists are allowed to disagree with each other and to investigate the various reasons for disagreement. I fear that by effectively only considering the datasets and studies that support their chosen narrative, the IPCC have seriously hampered scientific progress into genuinely understanding the causes of recent and future climate change. I am particularly disturbed by their inability to satisfactorily explain the rural temperature trends.”

Two Dozen Top Scientists: IPCC “Premature” Blaming CO2 Emissions…Warming Mostly From Natural Cycles

by P. Gosselin, Aug 18, 2021 in NoTricksZone


Most of the energy in the Earth’s atmosphere comes from the Sun. This new study found that the UN’s Intergovernmental Panel on Climate Change (IPCC) only considered a small subset of the published TSI datasets when they assessed the role of the Sun in climate change and that this subset only included “low solar variability” datasets. As a result, the IPCC was premature in ruling out a substantial role for the Sun in recent climate change.

A diverse expert panel of global scientists finds blaming climate change mostly on greenhouse gas emissions was premature. Their findings contradict the UN IPCC’s conclusion, which the study shows, is grounded in narrow and incomplete data about the Sun’s total solar irradiance.

The paper by 23 experts in the fields of solar physics and of climate science from 14 different countries is published in the peer-reviewed journal  (RAA). The paper, which is the most comprehensive to date, carries out an analysis of the 16 most prominent published solar output datasets, including those used by the IPCC.

Scientists come to opposite conclusions recent climate change causes 

The researchers compared them to 26 different estimates of Northern Hemisphere temperature trends since the 19th century (sorted into five categories), including the datasets used by the IPCC. They focused on the Northern Hemisphere since the available data for the early 20th century and earlier is much more limited for the Southern Hemisphere, but their results can be generalized for global temperatures.

No Mention Of CO2: New Study Shows African Climate Variability Strongly Linked To Natural Cycles

by C. Rotter, March 5, 2021 in WUWT


Africa climate variability linked to natural oceanic and solar cycles, a new study affirms. No mention of CO2. 

Understanding natural cycles the key to model projections

Sufficient rainfall is the basic condition for high-yield agriculture and food security for the population. Until recently, however, it was not possible to reliably predict rainfall several months in advance, which repeatedly led to unexpected crop failures. For some years now, however, progress has been emerging. The literature has repeatedly reported exciting correlations between temperature and air pressure patterns on the world’s oceans with rainfall and droughts in Africa and on other continents.

A group of researchers led by Horst-Joachim Lüdecke wanted to know more and meticulously searched for patterns in the monthly rainfall data of 49 African countries for the period 1901 to 2017 using statistical methods.

“Large number of robust correlations”

The scientists compared the rainfall fluctuations with five oceanic indices of natural origin that are firmly established in science, as well as with solar activity. The evaluation revealed a large number of robust correlations across the African continent with characteristic seasonal patterns. It has been known for some time that the Atlantic Ocean influences precipitation in Morocco and the Sahel via the so-called Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation (NAO). In East Africa, influences from the Indian and Pacific Oceans have been reported so far.