Saturday, March 14, 2015
Note: This program first aired on March 7, 2014.
This is a science and nature show and we’ve spent nearly 20 weeks looking at the science around climate change, but the dirty secret about climate change is that it is ultimately a social problem. And it’s a problem that doesn’t affect us all equally. Climate change has become as much a social justice issue as it is an issue for scientific research. We’ve said before on this program that life isn’t fair; we all have to die, and suffering is universal. Is it fair to the frog that the snake has to eat?
I don’t know the answer to that question but I do know this: Climate change isn’t fair, and here’s why. The people it will impact the most are the poorest people on earth. The people with the least ability to change their circumstances, and in many cases, the people least responsible for the mechanics of changing the climate in the first place. The Intergovernmental Panel on Climate Change is unequivocal: we suffer from “uneven risk distribution”, which is a fancy way of saying that wealthy nations will be able to insulate their citizens, for a time at least, against some of the extreme weather events, food shortages and security threats that climate change poses, poor nations will not. The intersection of uneven economic development and climate change exposure makes the world’s poor vulnerable to changing conditions in a way that most of us in the industrial world are not. And while we are all at eventual risk of social unrest and even violence if conditions get desperate enough, we already see the unrest and violence that has occurred in regions and nations that are environmentally on the brink.
In the near term, extreme weather events are the way in which most of us will experience climate change directly, in the form of more intense storms, colossally heavy rain fall, coastal flooding and heat waves that exacerbate drought and wild fire conditions. Droughts and floods, too much water coupled with not enough, these are what is on the agenda. Those two problems alone set in motion a cascade of human impacts; decreases in crop production and increases in food insecurity, decreasing freshwater resources for agriculture, industry and direct human consumption, and flooding in coastal zones and marginal recently urbanized land. These problems then compound themselves, as subsistence agriculture becomes more and more difficult in drought prone regions, human populations migrate increasingly to urban areas, colonizing marginal territory on the outskirts of cities, territory with little to no services. These people, driven from their homes by the inability to grow their own food and provide for their families and communities, then confront the other faces of climate change, namely the food insecurity that comes from rising food prices due to decreases in crop productivity, and the domestic insecurity that comes from moving into a rapidly expanding urban shanty town on marginal swampy land or steep hillside. Extreme precipitation events, monsoon rains, and typhoon storms easily flood these areas.
And we haven’t even considered sea level rise in this scenario. As the sea encroaches into coastal human landscapes the consequences are clear. Some low lying areas will be swamped all together, like the Pacific island nations or the Ganges River delta in Bangladesh, home to millions. Sea level rise is an existential threat to the people who live there. Large storm systems cause storm surges to threaten otherwise stable coastlines; low pressure and high winds, when coinciding with high tides can cause the ocean to rise much higher than its normal high water mark, as the people of the Philippines, New Orleans, lower Manhattan now know. And as freshwater aquifers are rapidly depleted and sea levels continue to rise, in coastal areas seawater seeps into these aquifers, filling the void created as freshwater is drawn out. Wealthy communities can for a time afford to purchase fresh water, poor communities cannot. Humans can survive only a matter of days with out fresh water, and salt water intrusion joins food insecurity and social unrest as yet another driver of human displacement and suffering with significant ties to climate change.
For most listeners of this show, the near future impacts of climate change may be uncomfortable, or economically challenging, but are unlikely to destroy our communities or fundamental way of life. The same cannot be said for the world’s truly poor. As the conversation around climate change pivots increasingly away from mitigation towards adaptation, we need to keep this in mind: it is in our local communities that we focus on adaptation, but it is for the global community that we must continue efforts to mitigate climate impact. We’ll look at how we do that in the coming weeks.
I don’t always agree with the World Bank, but they released a big report on this issue a couple of years ago: http://www.worldbank.org/en/news/feature/2013/06/19/what-climate-change-means-africa-asia-coastal-poor
Note: This program first aired on February 28, 2014.
We’ve come to the part of the climate change story that really matters. What is going to happen? What will the world look like for your kids and grand kids? How will it be different than it is today?
When we look at the ocean, the impacts of climate change are vast and many. The ocean covers 70% of the surface of the planet, and its’ medium, water has all the unique properties that make this planet hospitable to life. So you should expect anything that affects climate will affect the ocean in a big way, and it does.
Sea level rise is one of the first things people think of when they ponder the impacts of climate change. Some 44% of people world wide live within 150 km of the coastline, here in the US, that number is over 50%. The coastline though is an arbitrary location, relatively stable in the past few hundred years, our time frame for the modern world. The location of the coast is the result of a combination of factors; the amount of water in the ocean, the volume of the water in the ocean, and the level of the land, and it turns out all of these factors are dynamic. The current climate event is increasing both the mass and volume of the ocean. By melting land based fresh water ice caps (both large and small) the total amount of liquid water in the ocean is increasing, and as we all know, when you over fill a glass, it spills out. A second issue is at play, thermal expansion. As water warms the molecules spread out more, so the same mass of water will take up more space. Not only are we putting more water into the ocean, that water is getting bigger because it is warming up, increasing the volume of the ocean. How high will it go? The IPCC’s last projection was for approximately 0.4 and 0.7 meters of average sea level rise between now and 2100. Currently sea levels are rising at a rate of 3mm a year.
Things in the ocean are responding to changing water temperatures the same way things on land are to changing terrestrial climatic conditions, those that can move to keep up with their water temperature of choice are doing so. This is one of the main reasons we haven’t had a winter shrimp fishery here in the Gulf of Maine for the past couple of years. The commercially harvested Northern Shrimp (Pandalus borealis) are at the southern edge of their range here in Maine. Warming Gulf of Maine water is interfering with their reproduction, and populations have collapsed here as a result.
As ocean waters warm, ocean circulation is affected, particularly the vertical circulation that brings nutrients to the surface, and oxygen rich water to the bottom of the ocean. Increased warming at the surface creates a warm surface layer, effectively putting a cap on top of the ocean that prevents these vertical mixing currents (this is what happens on a small scale on the west coast of South America during an El Nino event). With no nutrients at the surface primary productivity drops dramatically. With no oxygen replenishment at the bottom, the bottom goes hypoxic. There is evidence from the fossil record that this kind of situation has happened before, and let’s just say, it wasn’t good.
The final elephant in the room is of course ocean acidification. This is a chemical phenomenon directly related to the increase in atmospheric carbon dioxide. As levels rise in the atmosphere, they correspondingly rise (by diffusion) in the ocean as well. When carbon dioxide mixes with sea water it forms carbonic acid, and uses up carbonate ions in the process. Carbonate ions are what calcium carbonate are made of, and animals that use calcium carbonate in their shells are very negatively impacted. Unfortunately those organisms happen to be important in the food chain, provide significant ecosystem services and are a significant part of many fishing dependent economies.
So you see, the impacts of climate change on the ocean are numerous and diverse and what happens on land also happens in the sea. There’s no place to hide. We’ll see what this really means for us next week.
UN Coastal Atlas:
IPCC 2013 report on Sea Level Rise: http://www.ipcc.ch/pdf/unfccc/cop19/3_gregory13sbsta.pdf
Island nations in threat: http://www.japantimes.co.jp/life/2013/09/06/environment/pacific-islands-fighting-for-survival-as-sea-levels-rise/#.VOzFv8bhJJM
Northern Shrimp in Maine: http://www.pressherald.com/2014/11/07/shrimp-depletion-in-gulf-of-maine-part-of-a-pattern-across-globe/
Under a Green Sky author Peter Ward (outlines the evidence that ocean stratification was related to mass extinction), on Vimeo https://vimeo.com/64407973
Gulf of Maine Research Institute on ocean acidification: http://www.gmri.org/news/waypoints/ocean-acidification-growing-concern-gulf-maine
NOAA on Gulf of Maine ocean acidification: http://oceanacidification.noaa.gov/WhatsNew/OANews/CurrentNews/TabId/552/ArtMID/1344/ArticleID/9991/Study-shows-Gulf-of-Maine-likely-to-be-more-sensitive-to-ocean-acidification-.aspx
Note: This program first aired on February 2, 2014.
Over the past weeks and months our climate change series has told us quite a tale about Earth’s climate system and how it is changing. We’ve looked at how the green house effect works and what gasses enhance it, what the parts of the climate system are and how they interact in very basic terms, and where the carbon comes from and where it goes. We’ve laid the ground work and now we’re coming to the final chapter of this story, the one in which we find out what happens next.
And what happens next is a story of degrees. If you have a chance, read through the Intergovernmental Panel on Climate Change’s 2014 Summary for Policy Makers-it’s available freely online. In it scientists clearly lay out the risks of various impacts on natural ecosystems and human societies. The devil is in the details, if global average temperatures increase only 1 to 2 degrees Celsius, the impacts are “considerable”. If temperatures increase 4 degrees or more, the risk become high or very high. The different in temperature increases reflect different emissions scenarios. Two things remain important to understand, first that under all assessed future scenarios some risk of adverse impact remains, and second, risks are substantially reduced under low emissions scenarios. Simply put, no matter what, change is coming, but we still have some say in just how much change it is.
And what can we anticipate in the coming century (and indeed it is a hundred year horizon that these predictions mainly look towards)? Where to start? Risks from climate change are extensions of much of what we see taking place already. As temperatures increase, so do the risks, significantly. If we look at the pure ecosystem impacts, we can anticipate a continued decline in biodiversity and an increased in extinctions for organisms that can’t adapt and or migrate to follow shifting favorable climate regions fast enough. Weakened ecosystems then become vulnerable to additional problems like diseases vectors and invasive species. These kinds of impacts are what many of us think of when we worry about climate change, as well we should, but we also need to remember that intact ecosystems provide vital services like cleaning water and air, and thus, negative impacts to natural ecosystems also have a negative impact on us. All of the other risks the IPCC report outlines are ones that directly impact the functioning of human society. Fresh water resources are projected to decline due to increased drought, especially in already semi arid areas. At the same time increased precipitation events are expected, which sounds like a good thing, except for when the additional inches of rain all fall at once. Then we have catastrophic flooding, and waste water systems that get overwhelmed, leading to increased pollution of surface water. High latitude areas may see increased freshwater resources, which brings up an important point—there can be effects that have a positive impact. Though, so far the projected negatives have outweighed the projected positives in virtually all areas of assessment.
Food security is another area where climate change is expected to negatively impact the human condition. Wheat, corn, rice and soy are the 4 most widely grown crops world wide, and increasing temperatures are projected in negatively impact the production of three of them (all but possibly soy). Decreased crop yields due to heat and water stress are likely to be the biggest issue, but problems arise with access and distribution as critical infrastructure is weakened by severe weather events. As annual crops, intensive breeding may be able to effect adaptation in a relatively short period of time, and had already yielded some more heat ready, drought tolerant varieties. The question remains, just how hot will it get? How much heat tolerance do we need to breed into these staple crops? These are just a couple of examples of what is coming between now and the end of the 21rst century. We’ll look at others in the coming weeks.
What we find as we dive increasingly deeper into the thought exercise that is “preparing for climate change”, is that while science has identified many negative ecosystem impacts, the things human society needs to pay attention to are the things that enable our “normal” day to day lives, the things that are easy to take for granted. Climate change seems very far away when you hear about a frog in the central American rain forest that has gone extinct, it’s much closer to home when you go to the sink for a glass of water and nothing comes out of the tap, just ask the folks in California. We’ve looked at the science, in this final chapter we’ll be looking at the human part of this story.
The Summary for Policy Makers (Summary being code for a document that is still 34 pages long) of the 5th IPCC report on climate change (2014): http://www.ipcc.ch/pdf/assessment-report/ar5/wg2/ar5_wgII_spm_en.pdf
This document is highly recommended, if still a bit dense. It contains many excellent graphics that accompany the assessment of risk.
Portland Press Herald (from the Washington Post) on the new NOAA NASA study: http://www.pressherald.com/2015/01/16/climate-change-milestone-outside-of-maine-2014-sizzled/
From Truthout and Bill Moyers, a shit ton of bad news,: http://billmoyers.com/2015/01/06/climate-disruption-advances-26-percent-mammals-face-extinction/
U S Navy predicts an ice free Arctic in ths summer by next year +/-3 years…