SHORT SUMMARY OF OBSERVATIONS UNTIL SEPTEMBER 2024

1: Observed average annual global air temperature change since 1979 (46 years) is +0.0151^oC (UAH). If this change rate remains stable in the future, additional average global air temperature increase by year 2100 will be about +1.135^oC.

2: Tide gauges along coasts indicate a typical global sea level increase of about 1-2 mm/yr. Coastal sea level change rate last 100 year has essentially been stable, but with periodic variations. If change rate remains stable, global sea level at coasts will typically increase 8-16 cm by year 2100, although many locations in regions affected by glaciation 20,000 ago, will experience a relative sea level drop.

3: Since 2004 the global oceans above 1900 m depth on average have warmed about 0.037^oC. The maximum warming (about 0.2^oC, 0-100 m depth) mainly affects oceans near Equator, where the incoming solar radiation is at maximum.

4: Sources and sinks for CO₂ are many. However, changes in atmospheric CO₂ follow changes in global air temperature, and changes in global air temperature follow changes in ocean surface temperature.

5: There is no perceptible effect on atmospheric CO₂ due to the COVID-related drop in GHG emissions 2020-2021, demonstrating that natural sinks and sources for atmospheric CO₂ far outweigh human contributions. Therefore, any future reductions in the use of fossil fuels are unlikely to have any significant effect on the amount of atmospheric CO₂.  

The whole point of science is to question accepted dogma.    Freeman Dyson.

MONTHLY REPORTS ON OBSERVATIONS

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Click here for information about book on climate published 30 November 2009. Now also as e-book.

ABOUT THIS WEBSITE: CLIMATE4YOU

The objective is to provide information on meteorological and climatologically issues of general and specific interest. 

The purpose is to assist reflective people to form a personal opinion on meteorological and climate matters. The purpose is not to provide a forum for discussions, as there are many fine web sites providing excellent possibilities for this.

It is definitely not the purpose to encourage a passive personal approach by providing a list of 'correct' answers to a list of 'key' questions, but rather to stimulate active, personal thought and analysis. The motto of the Royal Society of Great Britain: nullius in verba - take nobody's word for it, is still highly relevant.

The main emphasis of the present web site is therefore to provide the interested reader with data and other information on meteorology and climate. Climate change information needs to be both accurate and undistorted, and analysis unemotional. Respecting the notion that information always should be the starting point for personal thought, analysis and interpretation, links to information sources (digital and written) are provided throughout the web site.

The least objective part of the present web site is presumably the section on 'Climate Reflections', which is constructed around some of the webmaster's personal interpretations of certain data series. A slightly longer essay (in Norwegian) on the general climate theme can be downloaded by clicking here. An updated version of this text has been published as a book and e-book.

Some debates, books and other initiatives relating to global climatic changes, appears to be somewhat frustrated by an apparent lack of basic knowledge on updated meteorological conditions and their variations across time and space. Also when it comes to the likely effects of climate change, the lessons of history often appear to be unknown or forgotten. In Europe it is only little more than 200 years since the recognition that Earth is a dynamic planet began to transpire as a result of basic geological research. Previously, in Europe it was widely believed that Earth essentially was unchanging, and only about 6000 years old according to a study of the Bible by James Ussher (1581-1656), the Anglican Archbishop of Armagh, Ireland. Today it is equally easy to forget that it is only about 160 years since about one million people in Europe died of starvation and epidemic diseases because of climate-induced harvest failures. 

The recent focus on climate change has resulted in an increased awareness that climate is not as constant as it may have appeared previously. In this context, even the most extreme and divergent forecasts of future climate may have done some good. This is, however, a situation that should not continue much longer, as it confuses and disillusionates political decision-makers and the general public about the value of so-called ‘climate experts’. In addition, the initial humble scientific attempts of modelling the future climate have unfortunately developed into a large-scale example of groupthink with its own dynamics, making informed political judgment difficult.

Air temperature remains a central theme in discussions on global climate change, and admirable attempts to estimate the global temperature have been published by different research teams or -institutions. However, a number of issues relating to obtaining representative measurements of surface air temperature still remains, especially in or near areas affected by urban development. Even in Arctic regions it might be difficult to obtain representative air temperature measurements, despite all professional efforts. Also the varying degree of temporal stability displayed by the various global temperature records deserves attention. 

The difficulty of identifying a new climatic trend deviating from a background of natural variations is therefore real and constitutes an important difficulty for both scientists and policy-makers. As an example: Is it possible to conclude that the late 20th century global temperature increase is unique in relation to previous temperature increases? Or could it just as well represent part of the natural temperature increase following the end of the Little Ice Age ? Click here to read a few reflections on this interesting question. Another important issue is the relationship between atmospheric CO₂ and global temperature in recent times ?

The immediate need for climate scientists appears to be improving empirical knowledge on climate change, past and present, and to understand the limitations of the different types of approach to forecasting climate. For the decision-makers the lesson presumably is to allow wider margins for future climatic change; cooler as well as warmer, wetter as well as drier, windier as well as less windy, etc. Preparing for warming only is properly not prudent. After all, modern climate change may just be a continuation of ever lasting natural rhythms of climate change.

Climate science is a highly complex issue where simplification tends to lead to confusion, and where understanding requires knowledge, openness to new hypotheses, thought and effort. Doubt is the beginning, not the end, of wisdom.

The present website is under continuous development, and updates and new material will be added whenever possible or relevant. A list of the most recent key updates are shown in the lower part of the panel to the left.  

Thank you for your interest.

Yours sincerely, Ole Humlum

Click here for bibliography.

Non numeranda, sed ponderanda argumenta.