Presentation on theme: "The Climate of the Earth: CO2 and “Climate Change” (=Global Warming) Note: “climate change” was a term invented by Republican pollster Frank Luntz, for."— Presentation transcript:
The Climate of the Earth: CO2 and “Climate Change” (=Global Warming) Note: “climate change” was a term invented by Republican pollster Frank Luntz, for the Bush Administration in 2003, for political reasons. I’ll use “Global Warming” as it’s more accurate and doesn’t have the political spin.
Is there a Scientific Controversy about the Cause of Global Warming? No. Climate scientists themselves are convinced by the evidence – global warming is human-caused, primarily by fossil fuel burning. And have been, for over 20 years AGW = Anthropogenic Global Warming, a useful abbreviation Millions of dollars of oil money is financing an ugly mis-information campaign to seed cynicism towards legitimate science in the American public and in politicians about the cause. See my website page on the politics here.See my website page on the politics here.
Note How The More Closely You Understand Climate Science, The More Convinced You are that Global Warming is Human-Caused
Are Global Average Temperatures Rising Significantly compared to Recent Geologic History? Yes.
Longer Term: Over Several Hundred Thousand Years - Ice Ages Ice Ages show a strong correlation with small changes in the Earth’s orbital ellipticity, orientation, and angle of the Earth’s spin axis. As these go through cycles – the Milankovitch Cycles – the amount of heat delivered to the Arctic Circle varies, showing a strong correlation with inducing Ice Ages Reason: Ice is its own refrigerant. White ice reflects incoming sunlight, radiates little IR. More ice means more reflection, means more cooling, means more ice… etc.
Without Humans to add large amounts of greenhouse gases (GHG’s) to the atmosphere, temperatures rose and fell with very slow geological changes (or occasionally, by a big comet/asteroid impact) Rising temperatures will slowly lower the amount of CO2 that can be dissolved in the oceans, pulling it out and adding to GHG warming coming out of an Ice Age. This mechanism explains why temperature rises preceeded CO2 rises IN THE PREHISTORIC GEOLOGIC RECORD. This is NOT relevant for today’s Global Warming, which is caused by GHG’s, not slow Milankovitch cycles or other slow natural changes. Note the Temperature Range: Roughly 6 degrees C. That’s the same temperature changes climate models say we can expect – not in ~100,000 years, but this century. So – YES – today’s global warming is significant!
So; Temperatures are Rising Rapidly. Do we Know for Sure that CO2 is Rising and in a Significant Amount? YES.
The Rising Atmospheric CO2 is clearly in Agreement with Rising CO2 emissions by Human Activity
Is there Other Evidence that Rising CO2 levels are Caused by Humans? Yes. #1. Carbon isotope ratio C 14 /C 12 in the atmosphere is dropping, exactly as calculations say it should, as very low C 14 /C 12 carbon from oil and coal dilutes the higher C 14 /C 12 carbon which has existed in the atmosphere for millions of years. (Note: C 14 is created high in the atmosphere from N 14 by high energy solar wind and cosmic rays), and C 14 decays in a few thousand, not hundreds of millions of years (when ancient plants were buried to produce today’s oil and coal reserves), so the C 14 /C 12 ratio from long-buried oil is extremely low. #2. Known production levels of CO2 from mining and oil production fit with the rate of observed rising CO2 levels. See following slides.
Global Temperatures vs Atmospheric CO2 vs CO2 Emissions by Humans – Last 1000 Years
So, OK – Temperatures are rising dramatically, and so are CO2 levels, and so are human generated CO2 Emissions. But, couldn’t there be other causes of global warming that might be as significant or more so, than human activities?
The ONLY Known Mechanism which produces Heating of the Lower Atmosphere AND Cooling of the Stratosphere – is: Rising Greenhouse Gas Concentrations
…And Observations Show that Indeed, the Stratosphere is Cooling
Another Key – Nighttime Temps Rising faster than Daytime Temps This is expected only from rising greenhouse gas concentrations, because of the lag effect of temperature rise during the day; hot ground at night can’t radiate away its heat because of CO2 blanket If the sun were somehow causing rising temps, you would expect day temps to be rising faster than night temps. We see the opposite…
DTR = Daily Temp Range: 2000 vs 1951.
But Couldn’t there still be something Else? Other Influences Causing Global Warming, Not Us? No. The green (greenhouse gas) Curve Dominates
Climate Modelling Has Improved Dramatically. Climate Models Can ONLY Fit the Observational Data if Man- Made GHG’s are Included
But What About Subtle, Indirect Causes… 1. Svensmark Hypothesis: Cosmic Rays causing cloud condensation nucleation, and low clouds would cool the surface, so maybe this amplifies the weak solar radiation effect? No – First, the theory doesn’t make sense. There’s plenty of potential cloud nuclei w/o having to make more from cosmic rays. Second, the observations don’t show a believable correlation, and third and most important – the solar cycle shows no trend for the past 60 years, precisely when global warming has been most severe and accelerating. While cosmic ray flux does correlate strongly with solar cycle, the observed correlation between solar cycle and temperatures is directly explained by the known (small) change in solar irradiance with solar cycle, only coincidentally with cosmic ray influx.
Svensmark’s is the Only Idea I’ve Seen which isn’t Outright Climate Denialism at Work…. And Yet You See that it, Too, is Wrong. The politics of climate is ugly. See my website for details. Look especially at the YouTube’s “Climate Crock of the Week” series, which are faithful to good science, and also entertaining. Linked near the top of this pagemy website this page
Industry Science – If Your Science Hurts Profits, Don’t Expect Objective Honesty! Example…
Conclusion – Industry “science” is suspect. Industry hires scientists to help it earn profits. If there’s a conflict between the Truth, and profits….. You can guess which wins It may not always be the scientists themselves who buckle under threat of losing their jobs – industry may simply ignore or de-fund studies which to not serve their profits Contrast with Academia, where support comes from the NSF, NASA, and generally unbiased funding sources. Academic scientists publish in peer-reviewed journals. Industry scientists often can’t make the grade in true journals, and end up having to publish in “trade journals”, which have a poor track record of objectivity.
What Are the Effects of Global Warming? Rapid melting of the Arctic. The long term ice of the Arctic Ocean is already almost gone, and predicted to vanish entirely in just 20 years! Greenland is losing ice at an accelerating rate Rising sea levels Desertification of the mid latitudes is accelerating Migration of tropical diseases to mid latitudes. Malaria is already now being found in south Texas Massive dying of forests as pests which used to be held in check by cold winters are now multiplying. This releases yet more CO2 Very Dangerous – Acidification of the ocean, destroying coral reefs and before the end of this century - all calcium carbonate shell- building animals, a key base of the food chain on Earth. We are in the midst of the 6 th Great Extinction – the Anthropocene Extinction. Half or more of all species of life on Earth are expected to be extinct by the end of this century. Caused by us, with Global Warming the single most important cause.
Rising Ocean Concentrations of CO2 and Dropping pH (Acidification) Clearly Observed
Worldwide Retreat of Glaciers
What About the Future? IPCC 2007 Predictions are not “Alarmist” Enough – why? (1) Greenland ice loss did not model lubrication of glacier bases by meltwater, being too poorly understood. In fact, Greenland is losing ice much faster than predicted as this base meltwater accelerates glaciers into the ocean
Using Observed Greenland Ice Loss Rates – Sea level rise will be 3 times higher than even the IPCC 2007 AR4 Predicted
More Alarming… The IPCC 2007 modelling did not include the effects of Arctic broken ice migrating out of the Arctic Ocean and into the warmer Atlantic, which is clearly accelerating Arctic Ocean ice loss. IPCC 2007 expected the Arctic Ocean would not be ice-free until We now expect it’ll be more like (see graph on next slide)
And Most Alarming of All… Studies show an ice-free Arctic would cause thawing of permafrost as far as 1500 km south of the Arctic coastline. This region contains more than twice the entire carbon content currently in the atmosphere. Worse by far, it contains 10 times the methane as is already in the atmosphere, just in the frozen lakes alone. These lakes are now melting. (methane is 25x stronger GHG than CO2) If all of this methane is released to the atmosphere, the Greenhouse Effect heating goes up by 400%. Then add in further heating due to higher humidity (water vapor is a power greenhouse gas too), and the above CO2 in peat, and climate change would be extreme and many times worse than the most pessimistic IPCC 2007 forecast See this video of the arctic lakes methane contentthis video of the arctic lakes methane content
Global Warming is Only a Symptom of a Larger Problem: Living Beyond the Carrying Capacity of the Earth According to Stanford studies, with current technology, our planet can support only billion people sustainably. We have 7 billion, heading up towards 10 billion. Topsoil can only be replaced on geological time scales. Modern agriculture and land use is causing a loss of 1% of our topsoil per year Our planet today can only sustainably support 7 billion people if they are reduced to a standard of living equivalent to that in Ethiopia – a place of widespread grinding poverty. Think about that.
Finally… Only 36% of Americans believe that global warming is caused by human activities, from a Pew poll in 2009 (AGW is far better understood and accepted in Asia and elsewhere)Pew poll in 2009 A poorly science-educated public is allowing the fossil fuel industry and the politicians they influence to commit a great tragedy. Both on the planet, and our children. My opinion, I hope I’m wrong, is that the 21 st century will be very ugly. Nolthenius’ First Law – People Learn the Hard Way The scientific studies and journal papers backing up and expanding on the content of this powerpoint can be found on my website’s climate page: Click here. I urge you to read it.Click here This is your future more than it is mine.