“We are the last generation that can prevent irreparable damages to our planet” (link) Rep. Alexandria Ocasio-Cortez, once said:

we only have 12 years or “the world is going to end.” (link)

Figure 1. Rep. Alexandria Ocasio-Cortez (D-NY). Photo by Cheriss May of NurPhoto, taken on Feb. 5, 2019. Prince Charles of the UK on July 11, 2019:

“Ladies and gentlemen, I am firmly of the view that the next 18 months will decide our ability to keep climate change to survivable levels and to restore nature to the equilibrium we need for our survival.” (link)

However, these absurd statements are not supported by even the most fanatical climate alarmists, like Kate Marvel (NASA), Gavin Schmidt (NASA), Katharine Hayhoe (Texas Tech), or Andrea Dutton (University of Florida) (link). The original inspiration for these statements came from a 2018 IPCC report entitled Global Warming of 1.5°C. Even the alarmist Scientific American does not think the world is ending in twelve years. We will discuss this IPCC report below, but first let’s look at some critical evidence that is not in the report. As usual the IPCC dodges the current benefits of warming and additional CO2, so we need to fill in this gap. A little over two years ago I posted an essay entitled “Calculating the Cost of Global Warming,” it did not calculate a cost, but discussed calculations made by others. Global warming and the increasing concentration of CO₂ in the atmosphere are not existential threats to mankind or to nature. Global warming will not go “runaway,” this idea, discussed here, has been discredited by climate change skeptics and by climate alarmists alike (see here and here for examples). So, given that global warming and additional CO₂ will not harm us, we are reduced to a discussion of the economic impacts and benefits, both positive and negative, of global warming and additional CO₂. Global warming and additional CO₂ are benefiting humankind today and will still be a net benefit for many years to come. Someday, if the worst climate change computer projections turn out to be true, there may be a net cost. To compute the cost of global warming we need to determine the net present value of the current and future benefits (negative costs) and the net present value of the possible future costs, after multiplying the possible future costs by the probability that they may occur. This calculation needs to be done at some chosen future date, the date should be far enough in the future that some positive costs could occur, but not so far in the future as to invalidate our climate and economic projections. Obviously, the longer in the future that we project the climate and its impacts, the less certain we are that they are valid. If the result is a negative cost number, then we have a net benefit to humankind and if positive we may have a problem if the cost is too high. Sounds simple enough, but the process is fraught with problems. In the words of the IPCC:

“Global economic impacts from climate change are difficult to estimate. Economic impact estimates completed over the past 20 years vary in their coverage of subsets of economic sectors and depend on a large number of assumptions, many of which are disputable, and many estimates do not account for catastrophic changes, tipping points, and many other factors. With these recognized limitations, the incomplete estimates of global annual economic losses for additional temperature increases of ~2°C are between 0.2 and 2.0% of income (±1 standard deviation around the mean) (medium evidence, medium agreement).” IPCC WGII AR5 Technical Summary, page 71.

The emphasis is added by the author. Currently, global economic growth is about 3% per year, 2.9% in 2019 and an estimated 3.3% in 2020 according to the International Monetary Fund. So, the maximum economic impact of 2°C, as estimated by the IPCC, would be recovered in less than a year using current growth rates. This is hardly a crisis but let us examine recent arguments and cost estimates. Projecting future climate Before any future costs can be estimated, we must first estimate what climate will do in the future. Projecting future climate is very uncertain as explained here. Determining how much impact humans have on climate is even more uncertain, see here for a discussion of how the IPCC (Intergovernmental Panel on Climate Change) has attempted to determine human influence. The quote suggests that there may be “tipping points,” they mean that human influence on the climate may “tip” the climate system into an unstable state causing some sort of catastrophe, but we can rule that out as discussed in the already cited post “Can Earth be Compared to Venus.” Basically, the large amount of water in our oceans dampens any changes in our climate due to the high heat capacity of water. Colin Goldblatt and Andrew Watson show us that it is impossible for a planet to go “runaway” by simply adding CO₂ to the atmosphere. The IPCC phrase about “catastrophic changes” may be suggesting that extreme weather might increase, but we’ve seen no signs of that, as explained here. The climate projections made by the Coupled Model Intercomparison Project (CMIP), the most recent being CMIP5 in 2014 are high relative to observations as shown in Figure 2 in a graph by Dr. John Christy. This graph was presented to the House of Representatives committee on Science, Space and Technology on February 2^nd, 2016.

Figure 2. A graph of CMIP5 global tropospheric temperatures (5-year averages) versus satellite and weather balloon observations. These predictions are for the Representative Concentration Pathway (RCP) 4.5, a moderate case. Source: House of Representatives report by Dr. John Christy. Nearly all the models overestimate current tropospheric temperatures, the average is too high also. The only model that comes close to the observations is the Russian model, INM-CM4. This model is structurally different from the others. Relative to the other models, it assumes a much smaller climate sensitivity to CO₂ and a larger climate inertia, due to the oceans and their large heat (storage) capacity. INM-CM4 does not predict dangerous or expensive warming. All the curves are smoothed to eliminate short term changes, like El Ninos, since climate is defined as a long-term state, that is, greater than thirty years. Economic Forecasts So, we’ve established that the current climate forecasts are problematic and that they probably overestimate the climate impact of increasing the atmospheric CO₂ concentration. Given this, one would think that taking the average output of these forecasts and feeding it into economic models to determine the impact of climate change on our economy would be problematic as well. But this is exactly what climate change economists do. Benefits of global warming and additional CO₂ In discussions of climate change, the rather obvious benefits of global warming and additional CO₂ are often ignored. Yet, global warming and additional CO₂ have increased the amount of land under cultivation and increased farm yields. The additional CO₂ has also caused the planet to become greener as measured by total leaf area. This is discussed here and in the post’s links and references. Additional CO₂ in the atmosphere causes plant leaves to have fewer stomates or breathing holes in their leaves, this causes plants to use less water and makes them more resistant to extreme temperatures and droughts. Warming increases the Earth’s vegetative area and the additional CO₂ causes plants to move into areas where they previously could not survive. It also allows plants to survive at higher altitudes on mountain sides because CO₂ is denser than air, this causes the proportion of CO₂ in air to decrease with altitude. These physiological changes to plants, due to rising levels of CO₂, have increased crop yields dramatically. Combined with improved fertilizers and rapidly spreading advanced farming technology, this has resulted in far less hunger in the world today. This is true even though the population has increased. Dr. Craig Idso has computed the monetary benefit of additional CO₂ here. In Table 3 of Idso’s report (page 11) he calculates that between 1961 and 2011, CO₂ has increased farm gross revenues, for the top 45 crops, by an astonishing three trillion constant 2004-2006 U.S. dollars. The crops showing the largest increase were rice, wheat and grapes. These crops saw increases of US$579 billion, US$274 billion and US$270 billion respectively. World population growth peaked at about 2.2%/year in 1963 and has been falling ever since. The actual growth peaked in 1989 at 88,000,000 people and this quantity has also been falling since then. Even so the global population is larger today than at any time in the past, mainly because people live longer today. Today’s population is around 7.8 billion people, more than twice as many as in 1961, yet people today have more food per person, not less, as seen in Figure 3. Part of this increase in food supply is additional CO₂ and warmer weather.

Figure 3. Total kilocalories (food Calories) of food per person around the world. Data source FAOSTAT. The atmospheric concentration of CO₂ today is about 400 ppm or 0.04% of the atmosphere. We are seeing the benefits to food production, farm productivity and the greening of our planet as I write this. There is no suggestion that the rate of farm productivity growth, due to increasing CO₂, will fall anytime soon. Plant productivity, due to increasing CO₂ will increase at least until the CO₂ concentration has more than doubled from today’s level, as seen in Figure 4.

Figure 4. Dr. Sherwood Idso holds signs showing the additional CO₂ concentrations used to grow four Eldarica Pines. The photo was taken by Sherwood Idso’s son, Dr. Craig Idso in 1989. The tree grown at “AMB” or ambient conditions on the left was grown with a concentration of about 350 ppm, the concentration in the atmosphere then. The tree on the far right, was grown in an atmosphere of 800 ppm CO₂, twice the concentration we have today. Used with Craig Idso’s permission. Thus, we have every expectation of continued growth in our food supply and aerable land area due to higher CO₂ concentrations for the forseeable future. The CO₂ concentration is currently increasing at a rate of about 2 ppm per year at Mauna Loa (see here), so it is unlikely reach 800 ppm in less than 200 to 300 more years, assuming some increased uptake by plant life. Other benefits of warming include lower heating costs in the winter and fewer deaths due to cold weather. Climate Change Hazards The most recent IPCC report on the hazards of global warming and additional CO₂ is entitled Global Warming of 1.5°C. It was published in 2018 and the downside risks of additional warming and CO₂ we will discuss next come from this document. We will focus on the key assertions from the “Summary for Policymakers.” The first assertion in the document:

“Human activities are estimated to have caused approximately 1.0°C of global warming above pre-industrial levels, with a likely range of 0.8°C to 1.2°C. Global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate.” (A.1, Page 6, Summary for Policymakers)

This estimate is based on climate models as discussed here. Figure 5 shows the HadCRUT4 global temperature record. It is produced by the Met Office Hadley Centre and the Climate Research Unit at the University of East Anglia. The NASA dataset closely tracks this dataset, as can be seen here.

Figure 5. The HADCrut 4.0 global surface temperature dataset. Source: Met Office Hadley Centre. The HadCRUT global surface temperature record shows a decreasing temperature trend of negative 0.0016 degrees per year from 1850 through 1910, an increasing temperature trend of 0.0138 degrees per year from 1910 to 1944, then decreasing again at a negative 0.0026 degrees per year from 1944 to 1977, and increasing again from 1977 to 2019 at a rate of 0.017 degrees per year. It is possible that a flattening of the temperatures started about 2000, but the 2016 El Nino appears to fit in with continued warming, only time will tell if we have flattened longer term or moved into another cooling trend. The trends displayed in Figure 5 start in 1850 in what we are assuming is the pre-industrial era, at -0.3°C and end in 2019 at +0.7°C. So, in this document, the IPCC is claiming that 100% of the warming is due to humans. This is somewhat at odds with their WG1 AR5 assertion:

“It is extremely likely that human activities caused more than half the observed increase in GMST [Global Mean Surface Temperature] from 1951 to 2010.” WG1, AR5, Page 60.

Figure 5 presents the current rate of warming as 0.0171°C per year. This is 1.7°C per century or 0.5°C in thirty years. So, if the current warming trend, as determined by a least square’s regression of the data since 1977, continues for another thirty years, we will achieve 0.5°C of additional warming. This is what the IPCC is claiming, 2050 is within the range they give in the report. It will be interesting to find out if that happens. WG1 AR5 says more than half of the warming since 1950 is due to human activities and Global Warming of 1.5°C says all of it is due to humans. The difference in the two assertions is not explained in the Summary for Policymakers. In WG1 AR5, they explain that uncertainty prevents them from being more precise. But, even in WG1 AR5, they assumed that natural forces did not play a role in modern warming (see Figure 6 and the explanation here). In Figure 6, “NAT” are natural forces, such as solar variability, and “Internal Variablity” are natural climate oscillations, like the El Nino/La Nina events. They assume that over periods of sixty years, these natural fluctuations sum to a zero effect, many others disagree as you can see here. Longer term climate cycles, that is longer than 60 years, have been well documented and longer-term solar cycles appear to correlate with them, although there is a furious debate about this in the Wattsupwiththat community. Thus, the IPCC assumption of zero natural influence on climate since 1951 has been seriously challenged by some. Other arguments against the assumptions illustrated in Figure 6 can be seen here and here.

Figure 6. The WG1 AR5 (page 66) likely ranges of warming forces, given in degrees C of warming, over the period from 1951 to 2010 due to greenhouse gases (GHG), humans (ANT), humans, except greenhouse gases (OA), natural forces (NAT) and internal variability. The second assertion in the document:

“Warming from anthropogenic emissions from the pre-industrial period to the present will persist for centuries to millennia and will continue to cause further long-term changes in the climate system, such as sea level rise, with associated impacts (high confidence), but these emissions alone are unlikely to cause global warming of 1.5°C (medium confidence).” (A.2, page 7, Summary for Policymakers)

They are simply saying that human emissions alone, to date, will cause warming of less than 1.5° for some time to come, even if we stop emitting CO₂ today. No argument there. But, the magnitude of the impact of CO₂ and other greenhouse gas emissions on climate is unknown. This statement, combined with the first assertion, like many others from the IPCC, implies we know the impact of man-made greenhouse gas emissions on climate with a fair degree of accuracy (±20%, or a “likely range of 0.8°C to 1.2°C”) and we do not. The impact of CO₂ alone, is only known to ±50% (1.5° to 4.5°C per doubling of CO₂) according to WG1 AR5, page 14. The third assertion:

“Climate-related risks for natural and human systems are higher for global warming of 1.5°C than at present, but lower than at 2°C (high confidence). These risks depend on the magnitude and rate of warming, geographic location, levels of development and vulnerability, and on the choices and implementation of adaptation and mitigation options (high confidence).” (A.3, page 7, Summary for Policymakers)

Given that warming to date has benefited humankind, made the planet greener, and supplied us with more food, why would we characterize 0.5° to 1°C of additional warming as a risk? Wouldn’t it be more logical and accurate to characterize warming, to date, as a benefit? Further, “climate-related risks” for whom? Aren’t deaths due to cold a “climate-related risk?” More people die from cold weather than warm weather. The fourth assertion:

“Climate models project robust differences in regional climate characteristics between present-day and global warming of 1.5°C, and between 1.5°C and 2°C. These differences include increases in: mean temperature in most land and ocean regions (high confidence), hot extremes in most inhabited regions (high confidence), heavy precipitation in several regions (medium confidence), and the probability of drought and precipitation deficits in some regions (medium confidence).” (B.1, page 9, Summary for Policymakers)

Laughably obvious and unalarming. If global average temperatures go up, hot extremes will increase in some regions, of course they will. There will be more precipitation in some areas, since higher temperatures generally lead to more precipitation, and colder temperatures lead to less. The probability of drought will increase in some regions, there is always a drought somewhere, so this is obvious as well. Later in the document they go further and speculate that risks from droughts are projected to be higher at 2°C of warming than at 1.5°C in some regions. What part of global do they not understand? They are wording much of this in such a way as to make obvious statements sound alarming.

“By 2100, global mean sea level rise is projected to be around 0.1 metre [4 inches] lower with global warming of 1.5°C compared to 2°C (medium confidence). Sea level will continue to rise well beyond 2100 (high confidence), and the magnitude and rate of this rise depend on future emission pathways. A slower rate of sea level rise enables greater opportunities for adaptation in the human and ecological systems of small islands, low-lying coastal areas and deltas (medium confidence).” (B.2, page 9, Summary for Policymakers)

Sea level has been rising for the past 18,000 years, as shown in Figure 7. If we take the construction of the religious monuments at Gobekli Tepe in southern Turkey as when civilization started, sea level has risen 60 meters (197 feet) since civilization began. The current rate of rise is very low at around 2 to 3 mm/year.

Figure 7. Sea level rise since the last glacial maximum. Author: Robert A. Rohde, source: Wikimedia. For more on sea level rise see here. The recent rate of global sea level rise cannot be determined accurately since our instruments are only accurate to several centimeters and the rate is between one and three mm per year, or about 4 inches per century to 12 inches per century. These are not alarming rates and allow coastal residents and their descendants plenty of time to either move to higher ground or build defenses, such as sea walls. Sea level rise is not a global problem, it is a local problem. Do not expect to be taking photographs of the Statue of Liberty halfway under water in your lifetime or in the lifetimes of your great-great grandchildren regardless of climate change. The next assertion:

“On land, impacts on biodiversity and ecosystems, including species loss and extinction, are projected to be lower at 1.5°C of global warming compared to 2°C. Limiting global warming to 1.5°C compared to 2°C is projected to lower the impacts on terrestrial, freshwater and coastal ecosystems and to retain more of their services to humans (high confidence).” (B.3, page 10, Summary for Policymakers)

This is obvious nonsense, colder weather leads to more extinctions, not warmer weather. See discussions here and here. The average temperature of the Earth’s surface for the past 500 million years, the age of complex life on Earth, called the Phanerozoic, is about 20°C (68°F), this is over 5°C (9°F) warmer than today. We are currently living in an Ice Age, which is a rare occurrence in the Earth’s history. A fact that drives this home is that mortality is much higher in the winter, at any location in the United States, than summer. As the Earth warms, there will certainly be more heat-related deaths, but the decline in cold-related deaths will be larger. Warming increases temperatures in winter more than in the summer. Warming also occurs more at high latitudes than low latitudes. Discussion The remaining assertions all depend upon the IPCC assumption that colder is better and warmer is bad. Further, and even more dishonest, is the assumption, against all evidence, that warming is always bad. They ignore abundant evidence that past warming has been beneficial. B.4 suggests that warming will increase ocean temperatures and lower ocean pH or “increase ocean acidity.” It ignores the abundant evidence that corals and other ocean life have built-in methods of adapting to changing temperature and pH, as discussed here. B.5 asserts that humans are at greater risk as temperatures rise, this is the opposite of what the summer/winter mortality data shows. Far too many studies seek alarming headlines by reporting absurd results, as discussed by Bjorn Lomborg:

“Journalists looking for alarming headlines get help from climate scientists who gloss over adaptation and from public-relations teams that know their audience. A 2018 paper looked at two scenarios. In the first, sea levels rise almost 3 feet during the next 81 years, yet no one thinks to change the height of a single dike anywhere in the world. That would cost $14 trillion globally a year. The authors acknowledge this wouldn’t happen: ‘It is clear that all coastal nations have and will continue to adapt by varying degrees to sea level rise.’ In the second scenario, they try to account for adaptation, though they assume that as soon as any nation gets as rich as Romania is today, it will freeze its efforts.” (WSJ, May 30, 2019)

The IPCC and the climate alarmist community have become experts in framing the discussion to avoid any conclusions that are different from their political agenda. They avoid any discussion of evidence that warming is beneficial or that adaptation is preferable to or cheaper than mitigation. Section C discusses how to achieve zero greenhouse emissions by 2050, which the IPCC believes is necessary to limit temperature increases to 1.5°C above the pre-industrial era. They do not show why this is necessary, nor do they prove why limiting greenhouse emissions will achieve what they say. After all, we might warm 1.5°C due to natural forces. Section C is a discussion of model results, but as we have seen the climate models have not been validated against observations. Section D is a logical bait-and-switch. They stop discussing observations, assume their models are perfect, change the goal from improving the planet and humankind to achieving their strawman goal of keeping global surface temperatures from exceeding 1.5°C. We have seen that warming, particularly warming from 1.5° to 2.0°C from the pre-industrial era, will almost certainly benefit humankind and nature. There could be some economic consequences in the far future, beyond the year 2100, but they will be small relative to the economic consequences of eliminating or radically curtailing the use of fossil fuels. The cost of mitigation Mitigation, or the reduction in CO₂ emissions in the hope that this will reduce the rate of warming, is extremely expensive as Bjorn Lomborg, Nobel laureate William Nordhaus and economics Professor Richard Tol have written. Richard Tol has written that climate change will have a limited impact on the world economy prior to the year 2100. Regardless of the IPCC warnings about man-made greenhouse gas emissions causing dangerous warming, Nobel laureate William Nordhaus has said that the costs of their proposed CO₂ cuts are not worth it. The IPCC refuses to compare the costs of ending the use of fossil fuels to the costs that might be incurred if temperatures rise. However, according to Bjorn Lomborg and the IPCC, the cost of potential warming might be 0.2% to 2% of global GDP, but as noted above that is not a problem, it is perhaps nine months or so of growth. Yet ending fossil fuels would cost the EU 24% of its wealth. Lomborg notes:

“the over-the-top reception to the latest IPCC report means that we are more likely to continue down a pathway where the costs [of mitigation] would vastly outweigh the benefits [of curtailing climate change].” WSJ, October 9, 2018

Perhaps this issue is clearer when we discuss energy poverty. This is defined by the International Energy Agency (IEA) as a family that spends more than 10% of its income on energy. Ten percent of Americans are in energy poverty and in Germany, which has very high energy costs due to their reliance on renewables, more than 30% of the citizens are in energy poverty. Calls for the government to do more to curtail the use of fossil fuels are disguised as selfless calls to action, but they disproportionately punish the poor. Conclusions The hysterical statements of an impending climate doom in 12 years are not supported by observed changes to date. The report does prove that the level of BS rises with report length, but it does not say the world will end in 12 years. What the report does say, is that we might reach 1.5°C of warming, since the pre-industrial era in the Little Ice Age, by sometime between 2030 and 2052. We place the beginning of the pre-industrial era at about 1850 when the HadCRUT global surface temperature record starts. The world’s surface has warmed about one degree since then, so they are saying we could warm an additional 0.5°C by 2030 to 2052. They claim this might cause some serious problems, but present no evidence of this danger, only unvalidated computer model projections and speculation. They ignore the abundant data that shows humankind is benefiting from the warming to date and will probably benefit from warming in the future (see here). As Professor Richard Tol (University of Sussex) has written:

“The impact of climate change on the economy and human welfare is likely to be limited at least in the 21st century.” (The quote, a discussion of his results and the link to his paper can be seen here.)

There is nothing new in Global Warming of 1.5°C. They rehashed the IPCC AR5 report and changed the “dangerous” temperature increase from 2° to 1.5° as a stunt to make the “danger point” appear to be sooner. The IPCC has presented no evidence that 2°C above the temperatures in the Little Ice Age are dangerous, much less 1.5°. This document is not a scientific document, but political propaganda.   This article appeared on the WattsUpWithThat? website at https://wattsupwiththat.com/2020/02/23/do-we-really-have-only-12-years-to-live/ ]]>