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THE TBGY LECTURE ON EXTREME WEATHER [LINK] 

1. This week we are looking back at some of the events that helped make 2019 a pivotal period for our planet’s climate. So sit back and get yourself ready for a roller coaster ride through twelve dramatic months in the next 15 minutes.
2. Here in the Northern Hemisphere, we catapulted into January on the back of an Arctic Report Card from the NOAA that showed the Arctic continuing to warm twice as fast as the rest of the planet resulting in younger thinner Arctic sea ice covering less area than in the past. The NOAA data show that the twelve lowest sea ice extents in the satellite record had occurred between 2006 and 2018 … and that increasing temperatures were continuing to drive decreasing snow cover and increased melting across the Greenland ice sheet.
3. Ironically, we also witnessed record breaking snowstorms in the heart of Europe causing chaos and mayhem even in well prepared nations like Germany and Austria where 12 people tragically lost their lives.
4. Meanwhile over in South America, severe flooding dominated the first month of the year with more than a third of the population in six major regions of Argentina getting evacuated to safer ground; and the Metropolitan Region of São Paulo in Brazil receiving 20 inches of rain in just 72 hours displacing more than 2,000 people
5. And similar numbers of casualties were suffered in Sulawesi in Indonesia as heavy rains, strong winds, and high tides caused rivers to over-flood??. The province recorded over a foot of rain in 24 hours (12.5) damaging thousands of homes and displacing at least 6,000 people (0.03%).
6. Back at the start of the year, Australia broke 17 temperature records in the first month with Adelaide at 46.6C and Port Augusta reaching an all time high of 49.5C. But even on the driest inhabited continent on earth the flood still arrived with with 20 inches of rain in 48 hours up in Northern Queensland forcing the state government to declare a disaster situation.
7. February brought the first climate report of the earth when the United Nations released what they called a road map to the December climate summit stating that 2019 was the LAST CHANCE of the international community to take expected action on climate change. In that same month Britain’s Institute for Public Policy Research published its own major report simply titled “THIS IS A CRISIS”! ???? … it was quite stark. Mainstream politics and policy debates have failed to recognize that human impacts on the environment have reached a critical stage; potentially eroding the conditions upon which socio-economic stability is possible.
8. And then, as if to reinforce the argument, a meandering jet stream and collapsing polar vortex caused the worst cold period in the United States for decades, effectively dumping the Arctic winter weather straight across the Midwest. At least 21 people were killed and 90 million (out of 480) endured temperatures of -17C with some regions dropping as low as -40C making them colder than the North Pole.
9. Almost everywhere else on the globe, a thing was beginning to take shape that would arguably come to define the entire year’s weather pattern; and that thing was severe flooding. February brought major floods and landslides to Peru killing 51 and injuring 79. Homes in Peru were washed away after the Perene River burst its banks. Brazil, Ecuador, and Colombia all got battered by rains and landslides causing at least 20 fatalities and displacing thousands.
10. And over in Pakistan, almost three months of flooding began on the 21st of February with 25 fatalities Baluchistan Province.
11. As we press relentlessly into March, a teenage climate activist named Greta Thunberg came to global attention for the first time when her climate protest strategy of bunking off school every Friday and sitting outside the Swedish Parliament holding a Strike for Climate placard caught the imagination of millions of other school kids and inspired the global school-strike-for-climate movement that went completely viral all over the world.
12. In the renewable energy arena, for the first time ever, solar and wind power were both declared cheaper than most coal fired electricity production, marking a key tipping point in the ongoing demise of the fossil fuel industry.
13. The month was marred by yet more extreme weather events with the deadliest cyclone ever to be recorded in the Southern Hemisphere, crashing into Mozambique, Malawi, and Zimbabwe. In an excruciatingly slow 5-day crawl across these three countries, cyclone Idai left a trail of utter destruction including 1,300 fatalities and countless missing.
14. Even as far south as New Zealand, a state of emergency had to be declared on South Island as bridges and roads were washed away; and power and communication lines were destroyed by what that country’s water institute described as “an atmospheric river” with its footprint stretching for 5,000 km all the way from the Seymour Sea. More than 3 ft of rain fell within 48 hours (19 mm/hr), the highest ever total for New Zealand.
15. And just when the farmers of the American Midwest were breathing a brief sigh of relief after the February Arctic freeze, the relentlessly torrential rains arrived there as well. The first “course” of 2019 was the wackiest on record in the United States. At least 3 people were killed. New record river levels were set in 42 different locations and at least a million acres of US farmland in 9 major grain producing states were completely flooded. By the end of March, only about 56% of the expected corn and soybeans planting had actually taken place.
16. Northern Hemisphere springtime marched “always” into April. And also marching onwards was a new bunch of upstarts calling themselves Extinction Rebellion or XR. This lot hit the international headlines as they mobilized tens of thousands of people from every region in the United Kingdom to converge on London bringing large areas of our capital city to a complete standstill for two whole weeks in an entirely peaceful very disruptive exercise to get across the four demands for climate mitigation. The XR movement has now gone pretty much global so expect to see a a protester glued to a building near you very soon.
17. April also saw the publication of the International Renewable Energy Agency’s “Roadmap to 2050” explaining how we might transform our energy and electrification over the next three decades. And of course, here at JHAT we had a good look at what they were suggesting, all of which you can see in more detail by clicking up there somewhere [LINK] (full text below).
18. The skies kept putting pressure on poorly prepared communities all over the planet. Floods continued to ravage countries across the Americas, Africa, Asia, Europe, and the Middle East – including Syria where the water has completely displaced the already displaced refugees in the camps of Idlib Province. India and Bangladesh were hit by Cyclone Fani, the strongest cyclone seen in that part of the world since 1999. Cyclone Kenneth hit Mozambique and Tanzania with a force greater than any storm those countries have experienced since records began killing at least a hundred people and causing damage estimated at a hundred million dollars. Meanwhile, just to the north, severe drought pushed nearly 11 million people in Ethiopia, Kenya, and Somalia towards extreme hunger and disease including cholera as crops failed, cattle died, and water sources became contaminated.
19. A couple of starkly contrasting declarations hit us greens in May of this year. Starting with the UK government, who, having met with a delegation from Extinction Rebellion, and also because of pressure from their own committee on climate change, officially declared a “Climate Emergency” and set the target for meeting net zero carbon emissions by 2050 – the first major economy to do so.
20. In that same week, in the 11th Ministerial Meeting of the Arctic Council, US Secretary of State Mike Pompeo gave a speech celebrating the rapidly declining Arctic sea ice and welcoming the almost unimaginably exciting commercial opportunities that would soon be made available by the newly opened Northwest Passage and access to previously unavailable Arctic fossil fuels – even going as far as to describe methane as “freedom gas”.
21. June marked the start of a long Northern Hemisphere summer dominated by extreme heat events. With almost 400 all time high temperatures being set, kicking off in India where some regions experienced temperatures surpassing 45C for almost 3 weeks. June 10th was the hottest day ever recorded in Delhi, of 48C. And this year also brought the hottest July ever recorded in that country. 65% of the population were exposed to temperatures above 40C every day! for over two months, the longest heat wave in India’s history.
22. Similar deadly heatwaves were also endured in Europe, North America, and Japan. And then, the wildfires began. Of course, wildfires happen every year but rarely with the magnitude we witnessed in 2019. California’s annual fires are probably the best known and this year’s wildfires there were particularly brutal. But fires were also raging out of control in the Arctic circle, in Southern European countries like Greece, Portugal, and Croatia. And all over South America during July and August.
23. China reaches into September with the second costliest typhoon of all time. Typhoon Lekima killed at least 28 people and a million people had to be evacuated to safety.  Storm Dorian battered the Bahamas turning out to be the strongest Hurricane ever to hit that country and one of THE strongest Atlantic Hurricane on record. Storm Imelda made land landfall on the Gulf Coast as the 5th wettest storm in US history dumping 40 inches of rain on Texas. And the relentless floods kept coming and coming causing major problems wherever they struck. In some cases, they struck places that hadn’t fully recovered from the first and last deluge during the year.
24. November proved to be a bit like ground hog day in the United States as a repeat of the polar vortex collapse at the start of the year that caused the Arctic to dump its frozen temperatures yet again across vast swaths of the lower 48 bringing record breaking low temperatures, closing many schools, and causing the cancellation of more than a thousand flights.
25. As we tumble into the final month of 2019, the United Nations held the COP25 climate conference in Madrid, Spain where the nations of the world spent two weeks discussing the new global carbon pricing program as to how it has significantly increased over nationally determined contributions towards reducing greenhouse gas emissions before concluding the conference with a complete failure to agree on how to move forward on either of those two crucial challenges.
26. And while all that was going on in the Northern Hemisphere, down in the Southern Hemisphere, Australia was witnessing the onset of late spring bush fires that would go on to reach catastrophically uncontrollable proportions. Right now, as I am standing here talking to you in the very last week of the year, the map of Australia looks a bit like most of it is on fire. The Prime Minister Scott Morrison has kindly returned from his family vacation in Hawaii and actually conceded on national television that there is no argument about the human influence on climate change and it’s impact on the severity of the bush fires his country is currently enduring.
27. And yet still, after all we witnessed around the planet in this dramatic and potentially pivotal year for our climate, cynics will be gently swaying in their rocking chairs saying things like so we’ve had some bad weather and some casualties but most people seem to be getting on with their everyday lives more or less as normal. So should we really be so upset and concerned about these apparent changes in the climate? I know sane folks will be comforting themselves with the re-assuring notion that our climate has always been changing and always will. It’s nature’s way; and we humans are spectacularly good at adapting and overcoming.
28. Trouble is though, right now, as we prepare to go into 2020, we’re only just at the very bottom of an exponentially rising curve of climate consequences. All the scientifically accepted indicators suggest that what we witnessed this year, far from being a freak year for weather, is actually set to become the baseline norm as we go through the next decade and beyond. The year 2019 showed us just 1C of extra atmospheric warming above pre-industrial can dramatically and dangerously alter our planet’s climatic balance.
29. On our current emissions trajectory, it will be 1C warmer than today in 20 or 30 years’ time and at least 3C warmer than today by the end of the century. So 2020 really does look set to be an historically important year in the fortunes of our civilization. Not to mention countless other species that are relying on us humans not screwing up.
30. Can our nations finally come together to reach consensus on rapid implementation of climate mitigation strategies? Will developed and developing nations cooperate and make sacrifices for the greater good of humanity? Or will we continue along the road of political polarization and inward looking tribal nationalism? I’ll let you have a think about that as you go through your Christmas dinner leftovers.

RESPONSE TO THE TBGY LECTURE ON EXTREME WEATHER

ISSUE#1: EVENT ATTRIBUTION:

RESPONSE: In the lecture, TBGY has presented 23 instances of extreme weather. It is claimed that they were caused by climate change and that such events can and must be controlled or moderated by taking climate action and that therefore their severity and tragic impact on human well being provide the needed rationale for urgent climate action to mitigate climate change as a way of relieving humanity from the dire impacts of extreme weather described in the lecture. The extreme weather events described in the lecture are listed below.

However, no evidence is provided to support the causation hypothesis – that these extreme weather events are not natural and they would not have have happened without AGW and that therefore these extreme weather events must have been caused by AGW. Instead the causation relationship between AGW and extreme weather is subsumed into the presentation of their harmful effects in terms of the damage done to life and property. The assumption appears to be that the more extreme it is the more likely it is to be a creation of fossil fuel emissions and that therefore it could have been prevented by taking climate action.

By contrast, climate science uses a procedure called “Event Attribution Science” to find evidence of such causation [CITATIONS] . Weaknesses in this procedure are described in a related post [LINK] . Briefly, Event Attribution Science derives from a bureaucratic tool of the UN called the Warsaw International Mechanism (WIM) devised to determine whether compensation for damage sustained by non Annex countries in extreme weather events were fundable under the UNFCCC. The procedure uses a large number of climate model runs to determine the probability of the extreme weather event with and without fossil fuel emissions in the industrial era. A sufficiently higher probability with emissions leads to a positive attribution.

The many flaws in this event attribution procedure are noted in the related post on event attribution [LINK] the most salient of which is that post hoc attribution is likely to contain confirmation bias [LINK] particularly so when the scientists in question have a vested interest in a positive attribution in the context of their openly stated position as climate activists [LINK] [LINK] .

However, in spite of its shortcomings, the Event Attribution procedure currently used by climate science is the minimum required evidence for attribution of extreme weather events to AGW. This minimum required procedure has not been carried out and TBGY has simply taken it upon himself to determine that the examples of extreme weather presented are the creation of anthropogenic global warming (AGW) and their impacts contain a horrific extent of human misery and that therefore they can and must be controlled with climate action in the form of cutting emissions.

Climate scientists are fairly diligent with respect to the evaluation of extreme events with the event attribution procedure but it takes some time for the work to be carried out and for the results to be published. Therefore, at this early stage in 2020, it is unreasonable to expect these studies to be available. Below is a list of event attribution studies published in 2019. None of the 2019 events are included in these papers. It is unreasonable to expect event attribution studies of events in 2019 to be available in 2019 or so early in 2020. The implied attributions in the TBGY lecture are therefore rejected on this basis.

LIST OF EXTREME WEATHER EVENTS ATTRIBUTED TO AGW

1. Record-breaking snowstorms in the heart of Europe.
2. Flooding caused by heavy rains in Argentina and Brazil.
3. Flooding caused by rain in Sulawesi, Indonesia.
4. Very high temperatures as well as heavy rains and flooding in Australia.
5. A meandering jet stream and a collapsing polar vortex caused the worst cold period in the Midwest of the United States for decades.
6. Major floods and landslides in Peru where the Perene River burst its banks.
7. Rain and landslides in Brazil, Ecuador, and Colombia.
8. Three months of flooding in the Baluchistan province of Pakistan.
9. The deadliest tropical cyclone ever to be recorded in the Southern Hemisphere struck Mozambique, Malawi, and Zimbabwe.
10. In the South Island of New Zealand heavy rains and flooding washed away roads and bridges and destroyed power and communication lines.
11. Torrential rains and flooding in the American Midwest setting record river levels and destroying crops.
12. Severe flooding in the Middle East displaced refugees in refugee camps in Syria.
13. India and Bangladesh were hit by Cyclone Fani, the strongest cyclone to hit this part of the world since 1999.
14. Cyclone Kenneth hit Mozambique and Tanzania with a force greater than any storm those countries have experienced since records began.
15. Severe drought pushed 11 million people in Ethiopia, Kenya, and Somalia to hunger, disease, crop failure, dying cattle, and contaminated water.
16. Summer heat wave in India with temperatures surpassing 45C for 3 weeks, the longest heat wave in India’s history.
17. Similar deadly heatwaves were also endured in Europe, North America, and Japan.
18. Brutal wildfires in California, in the Arctic Circle, and in the Southern European countries of Greece, Portugal, and Croatia.
19. Typhoon Lekima hit China as the second costliest typhoon of all time killing 28 people and dislocating a million people.
20. Hurricane Dorian battered the Bahamas. It was the strongest Hurricane ever to hit that country and one of the strongest Hurricanes on record.
21. Tropical Storm Imelda hit the Gulf Coast of the USA as the 5th wettest storm in US history dumping 40 inches of rain in Texas; and the relentless floods kept coming and coming.
22. In November, the Arctic Polar Vortex collapse brought brought “frozen temperatures” across the Lower 48 of the USA causing the cancellation of more than a thousand flights.
23. Australia was witnessing the onset of late spring bush fires that would go on to reach catastrophically uncontrollable proportions.

BIBLIOGRAPHY: EVENT ATTRIBUTION STUDIES IN 2019

1. Imada, Yukiko, et al. “The July 2018 high temperature event in Japan could not have happened without human-induced global warming.” SOLA (2019): 15A-002. The high temperature event in July 2018 caused record-breaking human damage throughout Japan. Large-ensemble historical simulations with a high-resolution atmospheric general circulation model showed that the occurrence rate of this event under the condition of external forcings in July 2018 was approximately 20%. This high probability was a result of the high-pressure systems both in the upper and lower troposphere in July 2018. The event attribution approach based on the large-ensemble simulations with and without human-induced climate change indicated the following: (1) The event would never have happened without anthropogenic global warming. (2) The strength of the two-tiered high-pressure systems was also at an extreme level and at least doubled the level of event probability, which was independent of global warming. Moreover, a set of the large-ensemble dynamically downscaled outputs revealed that the mean annual occurrence of extremely hot days in Japan will be expected to increase by 1.8 times under a global warming level of 2°C above pre-industrial levels.
2. Knutson, Thomas, et al. “Tropical Cyclones and Climate Change Assessment: Part I. Detection and Attribution.” Bulletin of the American Meteorological Society 2019 (2019).  An assessment was made of whether detectable changes in tropical cyclone (TC) activity are identifiable in observations and whether any changes can be attributed to anthropogenic climate change. Overall, historical data suggest detectable TC activity changes in some regions associated with TC track changes, while data quality and quantity issues create greater challenges for analyses based on TC intensity and frequency. A number of specific published conclusions (case studies) about possible detectable anthropogenic influence on TCs were assessed using the conventional approach of preferentially avoiding type I errors (i.e., overstating anthropogenic influence or detection). We conclude there is at least low to medium confidence that the observed poleward migration of the latitude of maximum intensity in the western North Pacific is detectable, or highly unusual compared to expected natural variability. Opinion on the author team was divided on whether any observed TC changes demonstrate discernible anthropogenic influence, or whether any other observed changes represent detectable changes. The issue was then reframed by assessing evidence for detectable anthropogenic influence while seeking to reduce the chance of type II errors (i.e., missing or understating anthropogenic influence or detection). For this purpose, we used a much weaker “balance of evidence” criterion for assessment. This leads to a number of more speculative TC detection and/or attribution statements, which we recognize have substantial potential for being false alarms (i.e., overstating anthropogenic influence or detection) but which may be useful for risk assessment. Several examples of these alternative statements, derived using this approach, are presented in the report.
3. de Abreu, Rafael C., et al. “Contribution of Anthropogenic Climate Change to April–May 2017 Heavy Precipitation over the Uruguay River Basin.” Bulletin of the American Meteorological Society 100.1 (2019): S37-S41.  The Uruguay River is a transboundary river of great economic importance in South America. Its headwaters lie in southern Brazil, the middle reach forms part of the Brazil–Argentina border, the lower reach forms the Argentina–Uruguay border, and it then empties into the La Plata River with a catchment area of 3.65 × 105 km2. The river basin has a temperate climate with annual mean precipitation of 1,750 mm with little seasonality. During the late twentieth century, the Uruguay basin had a positive trend in precipitation (Barros et al. 2008) and streamflow (Pasquini and Depetris 2007). Based on hydrological modeling, Saurral et al. (2008) attributed the 1960–2000 streamflow trend mainly to the increase in precipitation rather than land cover change. The upper Uruguay River catchment has relatively high relief, low soil storage capacity, and land use is mostly pasture and cropland. Therefore, the catchment has a fast hydrologic response in which flood occurrence is more dependent on meteorology than on initial conditions of soil moisture and flow (Tucci et al. 2003). A cascade of hydroelectric dams is used for flood control operations. However, when more persistent and intensive rainfall systems develop
   over the upper catchment, the high soil moisture, fast rainfall runoff response, and limited storage capacity of reservoirs overwhelm the flood control operations and result in downstream flooding. Flood related impacts have also increased, resulting in a growing concern regarding the need to identify the causes of increased flood frequency and establish effective mitigation efforts
4. Stone, Dáithí A., et al. “Experiment design of the International CLIVAR C20C+ Detection and Attribution project.” Weather and Climate Extremes 24 (2019): 100206.  There is a growing research interest in understanding extreme weather in the context of anthropogenic climate change, posing a requirement for new tailored climate data products. Here we introduce the Climate of the 20th Century Plus Detection and Attribution project (C20C + D&A), an international collaboration generating a product specifically intended for diagnosing causes of changes in extreme weather and for understanding uncertainties in that diagnosis. The project runs multiple dynamical models of the atmosphere-land system under observed historical conditions as well as under naturalised versions of those observed conditions, with the latter representing how the climate system might have evolved in the absence of anthropogenic interference. Each model generates large ensembles of simulations with different initial conditions for each historical scenario, providing a large sample size for understanding interannual variability, long-term trends, and the anthropogenic role in rare types of weather. This paper describes the C20C + D&A project design, implementation, strengths, and limitations, and also discusses various activities such as this special issue of Weather and Climate Extremes dedicated to “First results of the C20C + Detection and Attribution project”.
5. Kirchmeier‐Young, M. C., et al. “Attribution of the Influence of Human‐Induced Climate Change on an Extreme Fire Season.” Earth’s Future 7.1 (2019): 2-10.  In the coming decades, climate change is expected to dramatically affect communities worldwide, altering the patterns of many ambient exposures and disasters, including extreme temperatures, heat waves, wildfires, droughts, and floods. These exposures, in turn, can affect risks for a variety of human diseases and health outcomes. Climate epidemiology plays an important role in informing policy related to climate change and its threats to public health. Climate epidemiology leverages deep, integrated collaborations between epidemiologists and climate scientists to understand the current and potential future impacts of climate-related exposures on human health. A variety of recent and ongoing developments in climate science are creating new avenues for epidemiologic contributions. Here, we discuss the contributions of climate epidemiology and describe some key current research directions, including research to better characterize uncertainty in climate health projections. We end by outlining 3 developing areas of climate science that are creating opportunities for high-impact epidemiologic advances in the near future: 1) climate attribution studies, 2) subseasonal to seasonal forecasts, and 3) decadal predictions.
6. Young, Hannah R., et al. “Event Attribution science in adaptation decision-making: the context of extreme rainfall in urban Senegal.” Climate and Development (2019): 1-13.  Event attribution assesses the effect of climate change on individual extreme events. While scientists have suggested that results could be relevant for climate adaptation policy, this has had little empirical investigation, particularly in developing regions. Taking the case of Senegal, the national adaptation policy context regarding extreme precipitation and flooding in urban areas, and the scientific information needed to support this policy is investigated using key informant interviews, a workshop and document analysis. Flooding in Senegal was found to be viewed primarily as an urban planning concern rather than a climate change issue, with actions to address the impacts focussing on current vulnerabilities of urban communities without considering changing climate risks. While stakeholders thought event attribution might be useful to inform about climate change impacts and future risks of extreme events, it is unclear whether there would be an opportunity for this at present, due to the limited role climate information has in adaptation decision-making. While addressing vulnerability to extremes is necessary whether or not the risk is climate change-related, if long-term planning is to be resilient then knowledge about future changes in risks of extremes will need to be considered, even if individual events are not attributed to climate change.
7. Owen, Rebecca. “Actuaries are Paying Attention to Climate Data.” Bulletin of the American Meteorological Society 100.1 (2019): S5-S8.  magine it is July in a city in the upper Midwestern United States. Usually it is hot and muggy in the summer, with bugs flying and the lush greenery steaming. But this week the temperatures have soared far above the usual high 80s, and the nights bring no relief. Day after day triple-digit heat leaves most everyone limp and tired. But for some people, the heat is more than just a tiresome nuisance; it is life threatening. The city has a large low-income elderly population, with a large percentage suffering from chronic obstructive pulmonary disease, diabetes, congestive heart failure, and kidney disease. Their old houses and apartments do not have functioning air-conditioning and they are reluctant to go outside or to ask for help. The heat wave is life threatening for them and they have few resources and amenities to cope with the heat stress. The hospitals that serve them are stretched to capacity normally; now the emergency rooms need to turn away ambulances and there are no more vacant beds for patients in extremis. The euphemism for the result is “increased morbidity and mortality due to heat-related causes.” The blunt statement is that the heat is making people very sick or even killing them. This is of course, not a far-fetched scenario, since we have read the news stories including from Chicago, Paris, and Sydney. Nor are scenarios featuring floods in the Southeast or tornados in Oklahoma or drought-exacerbated fire in the West. These events are all driven by climate, and in a world where the climate is changing, so is the risk of any of these scenarios occurring. In this article I provide an overview of how and why actuaries assess various risks, and the role a changing climate can have in those calculations. For climate scientists, I hope this provides insight into how event attribution research can be relevant to actuaries.
8. Ribes, Aurélien, Soulivanh Thao, and Julien Cattiaux. “Describing the relationship between a weather event and climate change: a new statistical approach.” (2019).  Describing the relationship between a weather event and climate change – a science usually termed event attribution – involves quantifying the extent to which human influence has affected the frequency or the strength of an observed event. In this study we show how event attribution can be implemented through the application of non-stationary statistics to transient simulations, typically covering the 1850-2100 period. The use of existing CMIPstyle simulations has many advantages, including their availability for a large range of coupled models, and the fact that they are not conditional to a given oceanic state. We develop a technique for providing a multi-model synthesis, consistent with the uncertainty analysis of long-term changes. Lastly, we describe how model estimates can be combined with historical observations to provide a single diagnosis accounting for both sources of information. The potential of this new method is illustrated using the 2003 European Heat Wave and under a Gaussian assumption. Results suggest that (i) it is feasible to perform event attribution using transient simulations and non-stationary statistics, even for a single model, (ii) the use of multi-model synthesis in event attribution is highly desirable given the spread in single model estimates, and (iii) merging models and observations substantially reduces uncertainties in human-induced changes. Investigating transient simulations also enables us to derive insightful diagnoses of how the targeted event will be affected by climate change in the future.
9. Wehner, Michael F., Colin Zarzycki, and Christina Patricola. “Estimating the human influence on tropical cyclone intensity as the climate changes.” Hurricane Risk. Springer, Cham, 2019. 235-260.  Quantifying the human influence on individual extreme weather events is a new and rapidly developing science. Understanding the influence of climate change on tropical cyclones poses special challenges due to their intensities and scales. We present a method designed to overcome these challenges using high-resolution hindcasts of individual tropical cyclones under their actual large-scale meteorological conditions, counterfactual conditions without human influences on the climate system, and scenarios of increased climate change. Two practical case studies are presented along with a discussion of the conditions and limitations of attribution statements that can be made with this hindcast attribution method.
10. Harrington, Luke J., and Friederike EL Otto. “Attributable damage liability in a non-linear climate.” Climatic Change 153.1-2 (2019): 15-20. Addressing questions of loss and damage from climate change in courts is limited by many scientific, legal and political challenges. However, modifying existing extreme event attribution frameworks to resolve the evolution of the impacts of climate change over time will improve our understanding of the largest scientific uncertainties.Loss and damage from anthropogenic climate change has been formally realised in the Paris Agreement of 2015 as a third pillar of climate change action next to adaptation and mitigation (Paris_Agreement_text 2018). However, political obstacles have resulted in intergovernmental compensation measures being explicitly excluded as a means of addressing loss and damage (Paris_Agreement_text 2018).

RESPONSE TO THE TBGY LECTURE ON EXTREME WEATHER

ISSUE#2: THE LAST CHANCE TO TAKE CLIMATE ACTION:  TBGY states in his lecture that “February brought the first climate report of the earth when the United Nations released what they called a road map to the December climate summit stating that 2019 was the LAST CHANCE of the international community to take expected action on climate change. In that same month Britain’s Institute for Public Policy Research published its own major report simply titled “THIS IS A CRISIS”! ???? … it was quite stark. Mainstream politics and policy debates have failed to recognize that human impacts on the environment have reached a critical stage; potentially eroding the conditions upon which socio-economic stability is possible.” 

RESPONSE: So now that the LAST CHANCE has come and gone while we are already in a CRISIS are we doomed? Or is there going to be yet another LAST CHANCE as in all those TIPPING POINTS that have come and gone? There is an optimum level of fear at which climate research funding is maximized. The idea that global warming is past the “tipping point” or a point of no return is well beyond that optimum. No funding for climate action or climate activism will be forthcoming if mitigation is not possible. Yet this LAST CHANCE tipping point argument has been used repeatedly in the past and as we see here, it is still being used. Things like this make it difficult to take climate science seriously as the objective scientific inquiry that it claims to be.

2007: WE PASSED THE CLIMATE CHANGE TIPPING POINT AND ARE DOOMED
Ahead of the Bali meeting in 2007, climate scientists flooded the media with press releases that were increasingly alarmist in their pitch to save the planet from fossil fuels, so much so that they got carried away and announced that it was too late to save the planet for we had passed the tipping point because the damage done by the carbon dioxide already in the air had put into motion irreversible non-linear changes that would lead us to climate doom whether or not we cut emissions. Soon thereafter, having realized their folly, they quickly reversed themselves just in time for Bali by saying that there was still time to save the planet after all.

2009: WE ARE APPROACHING THE ABYSS OF CLIMATE CHANGE
Between 2005 and 2007 the UN repeatedly declares that we have passed the tipping point and that it is “already too late to late. The planet is doomed. But in 2009, Ban Ki Moon contradicts his staff and describes the effect of carbon dioxide emissions on climate as “our foot is stuck on the accelerator and we are heading towards an abyss”. That we are not at the abyss yet and there is till time to act.

RESPONSE TO THE TBGY LECTURE ON EXTREME WEATHER

ISSUE#3: RENEWABLE ENERGY IS CHEAPER THAN FOSSIL FUELS: In the renewable energy arena, for the first time ever, solar and wind power were both declared cheaper than most coal fired electricity production, marking a key tipping point in the ongoing demise of the fossil fuel industry. 

RESPONSE:  Our energy infrastructure is a work in progress. It has evolved in the past from windmills, water mills, and beasts of burden to the energy portfolio we see today; and it will continue to evolve; but these changes will come in terms of innovation within the context of the market economy. If you have a better idea, bring it to the market and the market will separate winners from losers within an overall regulatory regime. If activism is needed to push your idea through, it is probably not a winner and if the electrification rate approach TBGY cited is a good idea it will be a big success in the marketplace. All the modern technological advances we enjoy today were selected through this natural competitive process. There is no room for activism in such matters. In fact, the need for activism suggests that it is not a good idea.

RESPONSE TO THE TBGY LECTURE ON EXTREME WEATHER

ISSUE#4: TROPICAL CYCLONES AND CLIMATE CHANGE: The lecture cites 9 tropical cyclones as impacts of climate change. They are Cyclone Idai, Cyclone Fani, Cyclone Kenneth, Typhoon Lekima, Tropical Storm Imelda, and Hurricane Dorian. 

RESPONSE:  The attribution of these tropical cyclones to AGW is assumed but no evidence, citation, or even a rationale is provided for this attribution. The assumed attribution is rejected on this basis. A high profile study from MIT back in 2005 did conclude that climate change has made North Atlantic Hurricanes more “destructive”. However, this study contains several fatal statistical flaws. As a result its findings have no interpretation. This study is described in a related post [LINK] . Tropical cyclones are called “cyclones” in the Indian Basins, “typhoons” in the West Pacific Basin, and “hurricanes” in the North Atlantic Basin although they are really the same thing. Their generic name is “tropical cyclone”. If climate change were increasing total global cyclone energy, we would see a rising trend in this measure globally for all tropical cyclones. However, no such trend is found in the data as seen in a related post on this site [LINK] . The generally held belief that tropical cyclones have gotten stronger and more destructive in the industrial era because of fossil fueled climate change derives from the idea that global warming increases sea surface temperature in the regions of the ocean where cyclones form and higher sea surface temperature puts more energy into them. A testable implication of this relationship is that there ought to be a statistically significant correlation between total global tropical cyclone energy and sea surface temperature; but no such correlation is found in the data [LINK] . It is also noted that the strongest tropical cyclone on record is the Bengal Cyclone of 1737 that occurred in pre–industrial times and that the strongest tropical cyclone of the modern era is the Bengal cyclone of 1970 that happened during a sustained period of global cooling when a return to Little Ice Age conditions was feared [LINK] .

RESPONSE TO THE TBGY LECTURE ON EXTREME WEATHER

ISSUE#5: EXTREME TEMPERATURE EVENTS: The lecture cites a number of localized extreme temperature events with an implied causal connection to AGW. Examples are: Adelaide 46.6C , Port August 49.5C, Delhi 48C, and extreme cold in the USA due to a meandering jet stream and a collapsing polar vortex caused by AGW. 

RESPONSE: AGW is not a theory about localized temperature events but about long term trends in global mean temperature. To claim localized temperature events as impacts of the long term trend in global mean temperature a causation hypothesis supported by the data must be presented. Below are four GIF images that cycle through the 12 calendar months showing lower troposphere temperature trends 1979-2019 for global means, the Arctic, the Tropics, and for Australia. The red line through the data represents a 3rd order polynomial regression curve. These curves represent the theoretical effect of AGW. To claim that localized temperature events were caused by these curves, the evidence for that causation must be presented at the least in terms of attribution analysis. That relationship cannot simply be assumed.

GLOBAL MEAN TEMPERATURE

TROPICS

AUSTRALIA

ARCTIC