Climate change is decisively here. And even softer skeptics are now beginning to agree about both its inevitability and extent. But do we really need to quit beef to address it? No, I want roast beef. You can. This week saw Goldsmith's College, part of the University of London, banned the sale of the meat on campus to help tackle the climate crisis. As a result, beef products will no longer be available on campus when the academic year begins in September. Alongside that, there'll be an additional 10p levy to be added to bottled water and disposable plastic cups. In order to discourage their use as the institution seeks to phase out single-use plastics, as well as install more solar panels and a quest to become carbon neutral by 2025. But when it comes to beef, doesn't this seem excessive? Well, it turns out not really. Because at worst, climate change poses an existential threat to humanity. The planets are fucking fire. It's widely acknowledged that warming beyond two degrees could create a cascade of feedbacks where two leads to three, three to four, four to five, five to six. That isn't coming immediately. It's not going to start next year. But what we know for the rest of this century is likely warming of around two degrees centigrade. In reality, that means declining crop yields, vanishing glaciers, which presently provide clean drinking water and desertification from Lisbon to Los Angeles. In this scenario, the UN predicts as many as 200 million climate refugees, with the rising populations of the global South, particularly in South Asia and sub-Saharan Africa, incapable of being supported unless they move. This is an actual crisis, got it? Yeah, it's really that bad. Well, does the prohibition of beef really make a difference? The answer, and this is coming from someone who has little time for private virtue and what is needed, its historic collective action, is decisively yes. A present we're using 1.6 times our planets by capacity. In addition, we were in an ecological overdraft, spending far more than we're putting in. Now, while some people might blame overpopulation for that, and often racialized way of assessing the problem, that's deeply unhelpful. Because if every humanate the average South Asian diet, we could easily sustain a planet of 10 billion. On the other hand, if everyone ate the typical North American diet, that figure would be close to 2.5 billion. The reason? The role of animal products. So if everyone were to enjoy the same diet as the average American does today, consuming approximately 3,700 daily calories, we would need the resources of an additional 5 Earths. Even if you wanted the United States of today to be a template for global development, from the perspective of bio capacity, that isn't remotely possible. And when you integrate reasonable forecasts about the impact of climate change in agriculture, the picture gets even worse. A 2009 report predicted that warming of 3 degrees would mean a 50% reduction in wheat yields in South Asia between 2000 and 2050. Along with a 17% reduction in rice and 6% in maize. That's in a region with three of the world's eight most populous countries, India, Pakistan and Bangladesh, all of which are set to see their respective populations rise further still. Now, that isn't to say that the comparatively wealthier countries of the global North will remain unaffected, however. Within a low warming scenario, forecasts suggest the US would see corn and soy yields fall by 1346% respectively. Given the country as currently the world's leaning exporter of grains, that would spell disaster, not only at home, but for the world market. And even if other countries such as Russia and Canada could step up to become agricultural powerhouses, this might only serve to increase the possibility of resource conflicts with their more militarily powerful neighbours. So how can we possibly feed a world of 9.5 billion 30 years from now? Part of the answer, particularly for the global South, is cellular agriculture. Beaf without cows, land without sheep, foie gras without geese. That would necessitate less land, labour and water while creating a fraction of the CO2 and methane emissions. But while that technology is exciting and a massive part of the solution, it isn't yet here, which means as many of us as possible need to follow the example set by goldsmiths. That's because compared to a plant-based diet, meat is incredibly energy intensive and highly inefficient in converting solar energy to food. A Bangladeshi family living off rice, beans, vegetables and fruits can subsist on acre of land or less. Meanwhile the average American who consumes around 270 pounds of meat a year could require 20 times that. If you examine the inputs necessary to produce a pound of soy, compared to animal protein, the latter uses 12 times as much land, 13 times as much fossil fuels and 15 times as much water, and so is a famously inefficient non-meat product. And it isn't just the conversion of solar energy into kilo calories, which is inefficient. Nearly a third of the usable surface area of the planet is given over to livestock. Whether directly or indirectly, with animal feed, accounting for the majority of global crop production. One study by Cornwall University found that while 300 and 2 million hectares were given over to livestock in the US, only 13 million hectares were allocated to vegetables, rice, fruit, potatoes and beans. What small or livestock farming alone contributes to 14% of all human-caused greenhouse gases, and according to a 2006 report by the UN, generates more CO2 emissions than cars. Meanwhile, 69% of the world's fresh water withdrawals are committed to agriculture, most of which is in meat production, with the average cow consuming 11,000 gallons of water a year. That means the average pound of ground beef requires 440 gallons of water, and all in a world where millions of people die every year from water-related disease. Perhaps most remarkable of all is that after using all of this water, energy, land and labour, not to mention the greenhouse gas emissions created as a byproduct, we dispense with as much as half of the animal's carcass. A hethyl weighing 1,000 pounds will, on average, produce 610 pounds of what's called hanging weight, with this falling to 430 pounds of retail cuts after removal of bone and fat. Once you factor in skin and hooves, two years of digestive processes, consciousness, respiration and just moving around, food from a living cow starts looking incredibly wasteful as a means of transforming solar energy into beef and milk. Now, does all that mean you should quit eating meat right now and never touch it again? Until that is, we get cultured co-based dates? Well, probably. But I know it's very unlikely that you're going to do that, so let's start slow. Maybe like those at Goldsmiths, you could campaign for your school, university or workplace to go beef free. After all, beef is by far the most ecologically devastating meat. And while you're at it, why not be more mindful about reducing meat generally? I've gone back to being a vegetarian this year with the occasional lapse I must admit. And while that is certainly not enough to say the planet, along with limiting personal flights, it's a pretty decent start. What's more, eliminating meat from your diet, starting with beef, reduces unnecessary sufferings to your fellow creatures, who under capitalism are reduced to a lifeless commodity deprived of any dignity. One day soon, cellular agriculture, hopefully produced by a local worker and enterprise, will be providing you with ultra cheap lobster, caviar and rib-eye steak. But until then, do yourself the planet and the animals a favour. Reach for the salad.