Emissions and Climate Change
The agenda of the United Nations Conference on Climate Change, Paris, 30 November- 11 December 2015 has as a principal topic the rate of emissions of greenhouse gases (GHGs), particularly CO2 (https://www.cop21.gouv.fr/en/learn/). Of particular concern is the global warming, and accompanying weather extremes and sea level rise, projected to result from the GHG emissions. Although this is a complex topic, some basic numbers can be developed to give an idea of what might happen to global temperatures.
The annual increase in CO2 concentration is presently 2 ppm/yr = 20 ppm/decade. The increase in the atmospheric temperature has recently been approximately 0:13oC/decade. Thus, a CO2 sensitivity of [0.13 / 20] = 0:0065oC/ppm can be used to estimate the global temperature increase from CO2 emissions.
For example, the increase in CO2 concentration from 1850 to 2015 was 120 ppm corresponding to a temperature increase of (0:0065)(120) = 0:78oC= 1:40oF in agreement with reported values. For a total increase of 2oC, which is a critical value that is now often quoted, the increase in CO2 would have to be 2/ 0.0065 = 308 ppm. At the current rate of CO2 increase, the required time would be
308/2 = 154 yr. However, this time interval is probably too long since the rate of emission of CO2 will substantially exceed 2 ppm/yr at current rates of increase of CO2 emissions.
For example, if the average rate of CO2 emissions increases to 3 ppm/yr, which is quite likely in the near future of a few decades, the time to reach 2oC will be 308/3 = 103 yr or approximately one century. And the CO2 will remain in the atmosphere for centuries, so the temperature increase will most likely not be reversed for a long time. This analysis, while simplistic, indicates the urgency of reducing the CO2 emissions rate rather than allowing it to increase as it is now.
Submitted on 12th November 2015
A. J. McHugh, Lehigh University
G. W. Griths, City University London
W. E. Schiesser, Lehigh University
CO2 and Global Warming: The long-term perspective
We must hope that the coming COP21 meeting in Paris will recognise that global warming is for the long term, outweighing the general concern about the next few decades.
CO2 dissolves increasingly as oceans cool and is released to the atmosphere as they warm, with the total constant for the duration of the ice core record. Natural sequestration of the fossil fuel CO2 will require millions of years. It will remain as an added constituent of the surface environment. We are causing a permanent effect. The tipping point concept is irrelevant.
The present rate of global warming is slow because 90% of the greenhouse-induced heat is absorbed by the oceans. Even with a constant atmospheric CO2 concentration they would take 100 to 200 years to catch up with the atmospheric temperature. Then accelerated global warming will cause the rate of sea level rise to be about 4 metres/century, producing generations of climate refugees. A mean global temperature rise as small as 2°C is an impossible hope. The next two ice ages have already been prevented and the intervening warmer periods will be hotter than at any time in the last million years.
For our detailed arguments see: ‘The Earth as a cradle for life: the origin, evolution and future of the environment’, World Scientific 2013.
Submitted on 16th November 2015
Jane Hodgkinson and Frank Stacey
CSIRO, Brisbane, Australia
Climate change is Real and Man-Made, but right culprit should be found first
With the world's leaders meeting to discuss climate change at COP21 in Paris, France, starting from the end of this month, it seems most appropriate to comment on the topic of climate change at this moment.
In contrast to being portrayed as a skeptic of climate change by some biased politicians and environmentalist bloggers, I have shown that climate change is real and is mainly man-made in my scientific publications.
The above conclusion seems not always satisfactory to all politicians and scientists. Some of them have something to argue—the overwhelmingly accepted climate models have told that climate change is caused mainly by anthropogenic carbon dioxide (CO2). This is also the conclusion delivered in IPCC Reports.
The climate models, however, do not agree with the observations of global surface temperature changes for the periods of not only the past 16 years but prior to 1930 (the pre-CFC era) and of Antarctic stratospheric temperature change since the 1950s as well. The world leaders and policy makers should be aware of this fact.
My observations show that climate change is caused predominantly by man-made chlorofluorocarbons (CFCs), the substances that also lead to the ozone hole over the Polar Regions.
The observations, documented in my recently published book, “New Theories and Predictions on the Ozone Hole and Climate Change”, show strong evidence that the warming effect of rising CO2 has not been observed. Moreover, quantifying the contribution of man-made halogen-containing gases (mainly CFCs) to climate change gives a nearly perfect match with observed global surface temperatures.
This is probably good news on the horizon. The successful execution of the Montreal Protocol has shown its effectiveness in controlling the ozone hole in the Polar Regions and in reversing the disturbing warming trend.
The world protocols should perhaps be focused on continuing the efforts to phase out the production and use of halogen-containing greenhouse gases including CFCs, HCFCs, HFCs, PFCs, etc.
With no doubts, environmental and ecological protection, air pollution control, and energy crisis are the topics of great importance to humans in the 21th century. But there is no solid scientific evidence to argue that CO2 would be the main culprit of modern climate change happening since the late half of last century.
Submitted on 19th November 2015
University of Waterloo, Canada