Climate change and health. Dr. Kristie L. Ebi #HealthLand – #TalentNetwork

Climate change and health. Dr. Kristie L. Ebi #HealthLand – #TalentNetwork

[Music] hello i’m christy ebi i’m a professor in the center for health in the global environment at the university of washington i appreciate your interest in learning more about climate change and health i’ll cover a few issues over the next few minutes and look forward to hopefully good discussions at the meeting you may have seen publicity over the last week or so about the release of the working group one report from the intergovernmental panel on climate change six assessment report this working group focuses on the physical science basis about climate change the working group two report on impacts and adaptation will be released at the end of february and the working group 3 report on mitigation will be released in march this cartoon shows you a clever summary of the key messages in that working group 1 report about the physical science basis showing the extent to which the earth is warmed it’s now 1.2 degrees celsius above pre-industrial temperatures what that means for a range of hazards that are important for our health and well-being and how climate change could change both mean temperature precipitation other variables and the extremes as we continue to put greenhouse gases into the atmosphere and then as the climate continues to warm the bottom shows you the range of actions that are needed in order to stop the cycle of emission of greenhouse gases higher temperatures and more extreme events i’ll show you just a couple of selected key findings in this working group one report as a backdrop to talking about the health risks of a change in climate this figure shows you changes in mean temperature and precipitation for changes in global mean surface temperature of 1.5 and two degrees above pre-industrial as i said the earth has warmed 1.2 degrees above pre-industrial it’s projected that the earth will warm to 1.5 degrees by 2040 perhaps sooner when the earth warms to two degrees will depend completely on our greenhouse gas emissions on the magnitude of emissions how rapidly we can reduce those as you look at the figures djf is december january february jja is june july and august and so you can see from the figures greater warming in north america particularly in the northern regions of north america during the winter season there will be warming of course during the summer season i’ll show you in a minute what that warming means for extremes for total precipitation you can see higher precipitation in most regions during the winter season and a reduction of precipitation in the summer season completely dependent upon region this is one of many figures in that report about the extremes this focuses on hot temperature extremes just over land looking at 10-year and 50-year events the scientists who work on the working group one report looked at the period 19 1850 to 1900 and determined what was the one highest temperature that occurred in a 10-year event and a 50-year event and then projected how often that temperature could occur and so you can see from both figures how much extremes could increase that as we look at the one and ten year event with warming at 1.5 degrees that one and 10-year event would be four times more likely at four degrees it would be 9.4 times more likely the 50-year event though the very extreme events would increase dramatically so you can see on the right-hand side under present warming that the one in 50-year event is already almost five times more likely and if warming goes up to 4 degrees it would be more than 39 times more likely what does this mean for our health and well-being the figure on the left shows you at the top these changing hazards associated with the mission of greenhouse gases and that those changing hazards interact with demographic socioeconomic environmental and other factors that influence the magnitude and pattern of health risks those interactions between climate and the range of factors that influence the level of risk then affect the exposure pathways we’re all so familiar with extreme weather events heat stress air quality and on across and at the bottom you’ll see a short list of the health outcomes that are being affected by changing weather patterns this is a short list there’s a much longer list of all of the health outcomes that are being affected already by our changing climate the figure on the right shows you what could happen with additional warming focusing just on heat ozone malaria dengue and other diseases carried by various species of 80s lyme disease and west nile fever as you look at these figures the zero line are pre-industrial temperatures up the y-axis you can see the increase in global mean surface temperature and as you look at each figure the white area is where it’s not been possible scientifically to detect that that particular system that particular health outcome has changed over time when the color turns to yellow it means that there has been detection attribution and that in fact the extent the burden of disease of for example heat related morbidity and mortality has increased due to climate change with an assessment of at least medium confidence when the color turns to red those risks are widespread when the color turns to purple they’re extreme for each one of these health outcomes you can see three figures the figure on the left is looking at projections under a world in which there’s high challenges to adaptation and mitigation the column in the middle is for a world in which we continue to muddle through there’s medium challenges to adaptation and mitigation and the right hand column is a world aiming to sustainable development you can see across these six health outcomes not only the extent of risk as we go into a warmer future without significant mitigation for example at four degrees c but also the importance of our development pathway and the choices that are going to be made in terms of being proactive timely and effective in implementing a range of adaptation options to increase the resilience of our communities and of our health systems there’s a wide range of populations and regions that are particularly vulnerable to a change in climate this is a summary from the fourth national climate assessment just giving a very short overview of the kinds of communities and individuals that are at much higher risk and the kinds of actions that can be taken so we understand a great deal about who and where is at risk although more still needs to be learned when we think about the health risks of a changing climate it’s not just population health it’s also our health care facilities these figures also from the fourth national climate assessment show charleston county and miami-dade county in the united states showing you how many hospitals are at risk from different categories of hurricane flooding these figures are not unique in so many coastal communities around the world there are healthcare facilities that are at high risk for storm surge and for flooding from hurricanes or typhoons and there’s a lot that can be done to reduce the consequences of a changing climate for our health systems and then for our health individually collectively and for our health care infrastructure this figure is taken from the world health organization operational framework on climate resilient health systems showing you the kinds of areas in which adaptation is needed i’ve highlighted service delivery and health information systems these are the two areas in which most people in schools of public health and where many ministries of health focus in terms of implementation but there’s lots of other actions that need to be taken such as having a health workforce that is competent to really address the health risks of a changing climate and of course the need for financing and leadership and governance i’m going to run through a few examples just to highlight the kinds of risks that are of concern to give you some ideas where you could do some additional research do some additional implementation to help us prepare for a warmer future i’m going to start with heat it’s the risk that’s been studied the most this figure is just for the united states but it shows you how much warming has already occurred in the united states during the summer since 1970 and so you can see significant warming in many parts of the united states we know that heat affects us physiologically these show the pathways of exposure to high heat and what that means in terms of the strain on our body and what it means for particular organ systems when people are exposed to very high heat and are unable to use their natural physiological mechanisms or to cool themselves with mechanical cooling for example and as the core body temperature rises there’s a range of organ systems that are affected most of the publicity at the time of a large heat wave are the number of people who die from heat stroke after a heat wave as one has access to all of the death certificates it’s typical to discover that there is a much larger number of people who died in the heat wave about half of which died from cardiovascular disease that when people have weak cardiovascular systems that excess heat the damage that’s caused from that excess heat then can put people into for example a heart attack that would not have happened otherwise almost all heat related mortality is preventable it is an area where it’s urgent to start implementing more heat action plans the heat wave that occurred in the pacific northwest in canada at the end of june was record-breaking it is virtually impossible for this event to have occurred without climate change the figure shows the map of how much the records were broken compared to the highest temperatures in the period 1950 to 2020 and you can see that many of these places broke temperature records by 10 degrees fahrenheit or more that’s about 5 degrees celsius or more and that is unprecedented having records broken by that amount that much is extremely rare as of today the current tally as death certificates still are being analyzed is that there was more than a thousand excess deaths during this three-day heat event that’s a thousand people who would not have died during that three-day period without the heat a recent publication took a modeling-based approach to do detection and attribution to determine the proportion of heat-related mortality that is attributable to human-induced climate change the assessment across more than 730 locations in 43 countries was about 37 of current heat related mortality or recent heat related mortality is due to climate change and you can see the distribution around different countries so there’s lots of potential for making sure that we reduce the current current burden of heat related morbidity and mortality going into the future the numbers of how many people could die in future heat waves depends both on the extent of climate change as you saw in the earlier figure and also on adaptation this again is just for the united states this paper estimated that currently about 12 000 americans die every year from the heat and the projections then out into the future depend on extent of greenhouse gas emissions which then translates into temperature change and on whether there is or is not adaptation similar to the figure i showed earlier this really reinforces the futures in our hands it’s both for our greenhouse gas emissions how rapidly we re-reduce those as well as how proactive we are in increasing the resilience of our health systems there’s lots of health impacts of heat i will just touch on one briefly which is worker productivity these are projections again for the united states out through past the end of the century depending on how quickly the earth warms for the number of worker days that are unsafe because of high heat levels you can see currently there are challenges in the central valley in california parts of nevada parts of florida and other places because of high temperatures particularly during the harvest season but also for all outdoor workers and then you can see with warming of two degrees and up to four degrees a very large increase in the number of unsafe heat level days and there’s much that can be done to address that on the left is an infographic in quebec about their heatwave early warning system listing some recommendations that can be taken by individuals on the right is a figure of how canada is approaching developing a new heat warning system taking into account a whole range of factors not just the current climate but also factors like warning fatigue trying to have a much more integrated system so that as people move from place to place in canada they get consistent warnings they don’t differ from place to place heat is not the only extreme weather and climate event of concern these are the 20 20 billion dollar weather and climate disasters in the united states there was 22 they cost the united states about 95 billion dollars these are just the billion dollar disasters they’re not the million dollar disasters or the 100 000 disasters just the million dollar disasters and when you hear people say that we can’t afford to mitigate a changing climate we can’t afford not to just for the united states to be spending 100 billion dollars a year on extreme events the very extreme events means that there’s lots we need to do to protect our communities so they can be much more resilient to a change in climate an area that has received relatively little attention are the mental health issues associated with in this case extreme flooding this is work from public health england looking at some of the extreme flooding events that occurred in the uk over the past several years these analyses looked at people who lived in houses that were flooded people who lived in houses that were disrupted their lives were disrupted but the house itself was not flooded and people living where they didn’t experience flooding you can see the very large differences in probable depression anxiety and post-traumatic stress disorder these individuals have been followed up and there continue to be differences between the flooding the disrupted and the not flooding three to four years after these flooding events so these are long-term impacts on individuals that then of course affect communities as well an area of particular concern for those of us who live in western states and in other regions of the world that are seeing a significant increase in wildfire hotter years higher wildfire risk and this is just the western states of course there’s been massive fires this year in greece and turkey and in other locations in addition to the west coast of the united states the right-hand figure shows you some of the health risks of wildfire smoke i’ll note that the air quality index is based on pm 2.5 this figure goes out to 120. during a recent period when the wind shifted and the area i live in experienced some of the wildfire smoke from some of the fires that are ongoing my neighborhood had an air quality index of 170. two years ago when there were very extensive fires in the state of washington and in oregon the air quality index in my neighborhood was closer to 300. so the exposures are very high and we know that they’ve got long-term health consequences allergies and allergies and asthma if we were in person i would ask how many people had allergies or asthma it’s usually a significant fraction as co2 concentrations are going up there’s more pollen for some of the some of the kinds of pollen that we are really allergic to as humans and the left shows you just for ragweed the length in the ragweed season in terms of number of days and you can see in northern regions there’s already been almost a month-long increase in the length of the ragweed season so when we do have seasons when we’ve got particular kinds of pollen those seasons are becoming longer and there’s going to be more pollen probably the biggest health risk of a changing climate will be under nutrition the figure on the left shows sharp reductions in crop yields under low and high greenhouse gas emissions in 2030 and 2080 the figure on the right shows that this translates directly into childhood stunting so the estimates are that as climate continues to change the impacts on crop yields will be significant particularly for children who live in poor areas and increase the level of under nutrition in children under the age of five and it’s not just temperature it’s also carbon dioxide itself that carbon dioxide affects the nutritional quality of what are called c3 crops these are crops that include things like wheat rice barley potatoes carbon dioxide promotes the growth of these plants which results in more carbohydrates it also results in less protein and essential nutrients looking at concentrations of carbon dioxide later in the century the experiments that have been done show that protein declines about ten percent the micronutrients decline about five percent and the b vitamins on average about 30 percent so very large reductions in the quality of our food and this of course is a bigger problem today in terms of hidden hunger than food security per se there are about 700 million people in the world who are food insecure there’s about 2 billion that have got micronutrient deficiencies so the projections for the impacts of these on our health and well-being are hundreds of millions of people could be affected later in the century moving on to vector-borne diseases always an area of high interest this is a figure again for north america looking at the distribution of two ticks that can carry lyme disease showing you at the top the present distribution and the bottom so the top and the bottom both show the present distribution and the distribution in 2050 under moderate greenhouse gas emissions for these two species and showing a significant expansion in the geographic range into regions where people are not used to these have are unprepared for these kinds of exposures and while the health systems need to find ways to educate both the health care providers and the general population on what to do when exposed another vector-borne disease of high concern is the diseases carried by aedes aegypti 80s alphapictus and other species of 80s i’ll focus primarily on dengue and this shows you that temperature and precipitation interact with a range of other factors to affect development survival and reproduction of these vectors one can use those relationships then to develop maps such as these the map in the upper left shows the climate suitability for 80s aegypti in the united states the present day is in beige and the future distribution towards the end of the century in about 2070 shown in the red so you can see a significant expansion of the geographic range but just having the mosquito present doesn’t necessarily mean you have disease transmission you have to have a summer that’s hot enough and long enough to be able to transmit the disease the figure on the right shows the change in the transmission suitability so an expansion of the range but not as large and again this is for 2070. however mosquito species capable of carrying dengue zika and other viruses were found several years ago in toronto toledo and detroit the question is not if we’re going to see a change in the geographic range of the diseases the questions now when and as with heat there’s lots of opportunities to be prepared to move from passive surveillance systems to using early warning and response systems so that the first case can be detected almost as soon as it occurs and that the health systems are prepared to implement a robust response and so the numbers of cases are significantly diminished and finally i wanted to mention another issue that is of importance this goes back to the working group one report that was released recently showing that every ton of co2 emissions that is emitted adds to global warming in about a linear relationship and there is now extensive research showing that there are significant health co-benefits from undertaking mitigation of reducing our exposure to red meat for example of eating less meat eating more local fruit and vegetable reducing point sources of carbon dioxide what comes out of for example coal fire power plants and increasing our active transport will result in much better health and if you value those avoided hospitalizations and you value the avoided premature deaths then the benefits of mitigation for our health are of the same magnitude or larger than the cost of mitigation we should be mitigating for our health thank you much for listening and i hope you have a very fruitful conference thank you
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Climate change and health. Dr. Kristie L. Ebi #HealthLand - #TalentNetwork

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