Chapter One. The Ocean is Dying. Superwatto's excellent zoo thread gave me an excuse to mention a 1998 Harper's article that had a profound influence on my personal doomerism: Planet of the Weeds. It was the first time I'd come across the idea that human population pressures were causing a mass extinction event comparable to what was then called the K-T extinction, but is now called the Cretaceous–Paleogene extinction event. David Quamman's piece painstakingly reviewed the then-current science behind the concept and gave a fairly bleak assessment of where we were heading, given the opportunities do do something about it framed against the rate of human population growth. Within 2-3 generations, we may see the end result of a biodiversity bottleneck that, even absent humans, would take 5-10 million years to heal. One of my hobbies over the last 15 years has been tracking the accuracy of David Quamman's piece. I can tell you for certain without any kind of pessimistic bias that the news is not good. At Quamman's writing, the human population was well under 6 billion. Since then we've added something like 17-18% to the total. All the population pressures exerted on biodiversity Quamman described have become that much more severe in a mere decade and a half. And one of the areas where the news is worst is the effect of the population on the world's ocean life. Keep in mind that the size of the human population depends heavily on harvesting ocean life for food. For most of human history, the space below the ocean's surface has been a black box. As long as food came out of it, no one asked many questions. The crash of the whaling industry in the 19th century marked a turning point when scholars became aware of the need to understand what was going on down below, not that much has changed. The history of the fishing industry since has been punctuated by an ongoing series of commercial extinction in various fisheries around the world. As wild stocks of edible fish deplete, the rise of aquaculture has kept the supply of seafood relatively steady. Yet this effort papers over the fact that aquaculture fish are mostly fed by trawling the oceans farther down the food chain for feedstock. But that's just part of the story. The other part is climate change, ocean acidification, the die-off of coral reefs, pollution, algae blooms, the spread of ocean deserts, and ever-increasing pollution of all kinds. One of the best statements of the problem comes from the 2011 International Earth system expert workshop on ocean stresses and impacts, which concluded that we've blown past the worst-case scenarios, including - the coral reefs are dying from global warming and ocean acidification "that indicate disturbances of the carbon cycle associated with each of the previous five mass extinctions on Earth" - the worst case scenarios are being matched in terms of arctic sea ice melt, Greenland ice sheet melting, release of seabed methane that are compounding problems such as distribution and abundance of marine species, distribution of harmful algae blooms, simplification and destabilization of the food chain, which further reduces marine life resistance to climate change - the combined impact of climate change, overfishing, chemical pollutants, plastic uptake into the food chain, nutrient runoff, etc. magnifies the effects and has lead to an expansion of ocean dead zones at an accelerating rate. The multiple stressors of human activity accelerates the phase shift from coral-dominated to algae-dominated ecosystems, meaning that "organisms of low nutritional value, such as jellyfish" begin to dominate ocean ecosystems. The conclusion: unless we take action now, we will ensure the next globally significant extinction event in the ocean, comparable to all five global extinction events of the past 600 million years. The longer we wait, the more difficult and expensive remediation efforts will become. What kind of action we can take: -Reduce CO2 emissions now. -restore marine ecosystems by: reducing fishing efforts to long-term sustainable levels reducing nutrient inputs (sewage and farming runoff) into marine ecosystems reducing oil, gas and mineral extraction from the oceans -use the UN security council and UN General Assembly to introduce and enforce effective governance of the high seas. Let's be clear. None of these things is going to happen within the next quarter century, as all of them are the direct results of human population pressures which will continue to grow more severe through the next quarter to half century. Even if we bring population growth to zero immediately, the current level of pressure sustained over several decades will still be enough to ensure a mass extinction event for marine life. What we need at a minimum is 1) zero global population growth plus 2) dramatic reduction of consumption levels in the industrialized world to more sustainable levels. We all need to live much more simple lives. Is that going to happen? Not soon, and not without catastrophe, which will certainly occur if we cannot prevent mass extinction across the ocean, which is a critical part of our food supply. And let's not forget that the same kinds of things are happening on land. Habitat destruction and reduction of biodiversity. Some of that won't have as big an effect on the human food supply, but other on-land events, such as the depletion of fresh water supplies and the degradation of land needed for agriculture, will have their own disastrous impact. 15 years after Quamman wrote Planet of the Weeds, his conclusion holds up pretty well. We're in the middle of a human population-caused mass extinction event, and we're going to have to ride it out.