by Lucy Hawking
Why is climate change a problem?
The average temperature of the Earth’s surface (across all places and times, land and oceans and so on) has increased by about one degree Celsius or thirty-three degrees Fahrenheit, since measurements with thermometers and other instruments became widespread in the middle of the nineteenth century. Celsius—also known as Centigrade—is the unit of measurement of temperature used by most countries in the world. It is based on zero degrees for the freezing point of water, and one hundred degrees for the boiling point. So one degree Celsius may not sound like much compared to the daily or seasonal fluctuations in temperature we all know, but what might seem like small changes in the average when measured in degrees Celsius can make a big difference to the climate.
The amount of carbon dioxide in the atmosphere has already increased by more than 40 percent since we started burning fossil fuels about 250 years ago. This has increased particularly quickly since the Second World War, as the worldwide growth of industry and changes of lifestyle, mostly powered by fossil fuels, have become more rapid. The gas can stay in the atmosphere for hundreds of years, so each year emissions of carbon dioxide add to the concentration. If we carry on at the same rate, the amount in the second half of this century could be two or three times the level it was before the Industrial Revolution.
If this rate of increase continues until the mid-twenty-first century—when a child starting elementary school this year would only be in their forties—it could cause the surface temperature to be forty degrees Fahrenheit or more higher than it was before industrialization. This would be a level not seen on Earth for tens of millions of years! We cannot know for sure what the temperatures would be, but there are real risks they could be that high. Remember that modern humans have only been around for about two hundred thousand years. It is difficult to imagine what the Earth would be like if the increase continues until the end of this century.
The changing climate is having some positive effects, such as reducing the frequency of dangerously cold weather in some areas, but it is also creating risks for many people. In poor countries inhabitants are more vulnerable to rises in sea level or increased extreme weather events like hurricanes or drought. Over the next century, many areas may become difficult to live in because of increases in floods or droughts. Some areas could become uninhabitable: they might be submerged between rising seas—an island, for instance, vanishing underwater—or turned into deserts. Many people, perhaps hundreds of millions, might need to migrate away from the worst affected areas. In some parts of the world this is already happening; people have to move out of their homes after their crops fail and their livestock can no longer survive.
Plants and animals are also being affected by climate change; many species are migrating toward the poles in response to the warming, and many are threatened with extinction. Overall the change could make people much poorer, and we may reverse the gains in incomes and life expectancy we have seen across the world in the last hundred years.
What can we do about climate change?
The climate responds relatively slowly to changes in the amount of carbon dioxide and other greenhouse gases in the atmosphere. This means that, as a result of our past activities, climate change will continue for the next twenty to thirty years, so we will have to make sure that people, homes, and businesses are more resilient to the impacts. This is usually called adapting to climate change.
But the effects of climate change are becoming more dangerous, so to avoid the worst effects we need to reduce and stop releasing carbon dioxide and other greenhouse gases into the atmosphere. This is known as climate change mitigation. This will be difficult because more than 80 percent of the world’s energy today comes from burning fossil fuels.
But we have lots of alternatives, such as producing electricity from renewable sources, including wind and solar power. And we can power cars and trains using electricity from renewable sources. Governments across the world can play a big role by sticking to an international agreement made in Paris in 2015 to cut annual emissions of greenhouse gases so that global warming stays well below thirty-five degrees Fahrenheit. And businesses can help by finding ways to reduce pollution and waste.
And we can build better cities in which people spend less time sitting in traffic jams and use public transportation instead. As well as allowing people to spend more time working and living productively, this would drastically reduce both greenhouse gas emissions and air pollution.
Although we need to make big changes, we know we can do this while also raising living standards around the world and tackling poverty. Climate change is an urgent problem, but the solutions are exciting, with new and better ways of generating and using energy. Towns and cities could be much more attractive. Our forests and grasslands could be much more resilient. And the ecosystems on which we depend, both on the land and in our oceans, could be much, much less fragile. We would all benefit, particularly the poorer people in all countries.
Perhaps you will be one of our future scientists and ecologists working with others across our planet to make a better world for the generations to come—a better world for everyone.
The Future of Food
by Dr. Marco Springmann
Many predictions have been made about the future of food. They range from “edible air” to “meals in a pill.” Highly engineered novelty food products have been the staple of food futurists, and indeed of early space missions. Had George been on board a spaceship in the 1960s, he would have had toothpaste-type tubes, with liquefied or puréed food for breakfast, some bite-sized food cubes for lunch, and maybe some freeze-dried food powders for supper. Not the most appetizing prospect!
But nutritionists’ early enthusiasm for vitamin pills and “meals in a pill” has now given way to a renewed focus on whole foods. Take the humble apple, for example: apples, like other fruits and vegetables, contain a complex mixture of thousands of compounds that protect cells from damage. When eaten in the form of the whole fruit, apples can help prevent us from developing chronic diseases such as cancer and heart disease.
Scientists have tried to extract what they thought of as the active ingredients—for example, vitamin C from fruit such as apples, vitamin E from green, leafy vegetables such as spinach, and beta-carotene from orange vegetables such as carrots. However, it has been found that eating those extracts in pill form does not have any preventive health effects in most cases, and could even sometimes lead to an increase in chronic disease. You do have to eat the whole food to get all the health benefits.
What George would now find in the canteen of a spaceship, or on board a space station, would resemble more what you can find in one down on Earth. How about some mashed potatoes, nuts, broccoli, and an apple a day?
Let’s get back to thinking a bit more about the future of food. For that purpose, it might be instructive to consider what influences what we eat, and how what we eat influences our health and our planet (and any future planets we might find).
I’ll start with what might seem like a simple question: Why do you eat what you eat?
Maybe you eat a specific meal because you like its taste, or you are hungry. Maybe you eat it because it is there, and somebody has prepared it for you. Why do you think that person chose to cook that meal and not something else? Why is that specific meal there to begin with?
Scientists consider a similar set of questions when trying to predict how and what the world might eat in the future. They start with what can and has been produced in the past, and where. In the UK, that would currently be milk, meat, wheat, and root vegetables such as potatoes and carrots; and of course also some fruit like apples and strawberries. Then they look at how many people are around to eat the food produced, how much money those people have to spend on their food, what other foods might be available somewhere else, and how easy it would be to exchange some foods that are closer for foods that are farther away.
What the scientists observed was: as people become
richer, they consume more in general, and in particular more meat, dairy, sugars, and oils, and less grains and beans. This observation raises two problems that we could be faced with in a future with more people and with higher incomes worldwide.
The first problem concerns our environment, and the second our health.
Many thinkers in the past two hundred years have been worried that we might not be able to produce enough food on our Earth to feed a growing population. Thanks to technological advances in the way crops are bred, planted, and harvested, that concern is one of the past. What has become a worry nowadays is whether we can produce our food in a way that does not harm our environment.
One of the greatest threats to our survival on Planet Earth could be climate change. And food has no small role to play here. Currently almost a third of all climate-change-causing greenhouse gases are emitted during food production. And that proportion is expected to grow in the future, in particular due to the expected increase in meat consumption.
Beef is by far the greatest culprit. Cows produce greenhouse gases in their digestive system by fermenting feed in their rumen, the first compartment of their stomachs. Yes, I’m talking about burping and farting! In addition, growing feed for cows and other livestock requires fertilizers that also emit greenhouse gases. As a result, beef produces about 250 times more greenhouse gases per gram of protein than crops such as lentils and beans, and more than twenty times more greenhouse gases per serving than vegetables. Other animal-based foods—such as eggs, dairy, pork, poultry, and some seafood—emit significantly less greenhouse gases than beef, while plant-based foods emit the least.
It is no surprise, then, that scientists, in order to save our planet, have called for people to move away from diets high in animal products toward more plant-based diets. And the food industry is eager to jump on board with soy-based meat replacements, algae extracts, and meats whose production might emit less greenhouse gas emissions—such as lab-grown meat or edible insects. Perhaps you will be one of our future scientists working in this area, helping to produce foods to feed the world without hurting our planet.
Thinking now of health: a move toward plant-based diets could also avoid some of the dangers that come with the otherwise expected increase in meat, dairy, sugars, and oils. Processed meats—these include burgers, sausages, and chicken nuggets, but also the battered, fried fish portion of a plate of fish and chips—have recently been declared carcinogenic. This means that they can cause anyone eating a lot of these foods over a number of years to be more likely to develop cancer in the future. And even unprocessed forms of pork and beef have been associated with greater risks of cancer and other chronic diseases.
At the same time, energy-dense foods that are high in sugars and oils—think of ultra-processed foods such as cookies, chips, fries, sugary drinks, and the like—are contributing to more people becoming overweight and obese, which is also associated with a greater risk of cancer and other chronic diseases. Sometimes those foods are described as “empty calories’—calories without any nutritional value. They do not make us feel full, and we often snack on them between meals. Others call such foods “junk foods.” I bet you can guess why.
Where does all this leave us? It seems clear that to avoid dangerous levels of climate change and unhealthy levels of diet-related diseases, the food of the future needs to deviate from the past trends of eating more and more meat, dairy, sugars, and oils. A healthy and environmentally friendly diet for the future would be low in unhealthy and emissions-intensive foods—such as most animal products and ultra-processed foods that are high in sugars and oils—but high in health-promoting and low-intensity foods, such as whole grains, nuts, fruits, vegetables, and legumes.
On your next trip to Mars, how about, instead of a beef burger with fries, you try a lentil-and-bean burger in a whole-wheat bun with some extra slices of lettuce and tomato? Throw in a toothpaste-like tube of algae if you feel fancy. And enjoy your favorite fruit as dessert. Bon appétit!
Plagues, Pandemics, and Planetary Health
by Dr. Mary Dobson
As George’s spaceship Artemis crash-lands in a scary future world, we are reminded of the horrors of the many diseases that have struck humanity over the past centuries. The Black Death of the mid-fourteenth century, killing around one-third of the known population, was undoubtedly the most devastating. What may surprise you is that scientists are still investigating its cause to this day, using tools such as DNA analysis. Was this “plague” transmitted to humans just by the black rat (Rattus rattus) and its infected fleas (as most schoolbooks will tell you)? Or was the story, as we are beginning to suspect, more complex than that? The answers to these questions could help us not just to understand the past but also to prevent present and future global health threats.
Our microscopic world
The word plague is generally associated with its two main forms—bubonic and pneumonic plague—and outbreaks of both can still occur. When infectious diseases like plague are widespread, as with the Black Death, they are often described as epidemics or pandemics. Infectious diseases are caused by crafty microscopic undercover agents (micro-organisms), which typically take the form of bacteria, viruses, or parasites. Not all micro-organisms are dangerous to humans but, when they are, they can be called pathogens.
Airborne pathogens can be spread from person to person—for example, by coughing or sneezing. But pathogens can also be water- or foodborne; or they can be spread by infected animals and biting insects. There are even theories that some disease-causing microorganisms might originally have come from outer space!
Since the late nineteenth century, generations of brilliant scientists have discovered the causes and chains of transmission of many infectious diseases, and it is through this understanding that we can come up with effective solutions to prevent them from spreading across our ever-increasingly interconnected globe.
But we still do not know all the answers, and there are incredible opportunities for you, the younger generation, to make a contribution toward uncovering the hidden secrets of our microscopic world.
The influenza pandemic of 1918–19
The year 2018 was the hundredth anniversary of the end of the First World War. It is also the centenary of one of the greatest global pandemics of the twentieth century: influenza. The so-called “Spanish flu” killed between fifty and one hundred million people across the world. The death toll was significantly greater than those killed on the battlefields. There was, at that time, no cure, no vaccine, and no understanding of the “invisible” virus responsible. But people soon learned that influenza was a highly contagious disease, and that “coughs and sneezes spread diseases.”
A renewed interest in this historic pandemic (and why this strain of flu was so lethal) has been sparked by the recent scares of avian or “bird” flu and the 2009 “swine” flu pandemic.
The SARS pandemic of 2003
It is maybe not as fast as George’s spaceship, but the speed of air travel around the globe has enabled the ever more rapid spread of pandemic diseases. Take, for example, the first major, and previously unknown, pandemic of the twenty-first century—SARS (severe acute respiratory syndrome). Like tweets that go “viral” via social media, infectious diseases can now circulate the globe in less than a day. In 2003 SARS “jetted” from China to Hong Kong to Canada, and on to almost every continent, before eventually being contained through public health action coordinated by the World Health Organization (WHO).
Luckily, scientists across the world were able to track the progression of the disease, share their findings via the Internet, and rapidly identify its cause—a virus intriguingly related to the common cold but far more deadly.
Headline news: Ebola and Zika viruses
Scientists have in fact found that many infectious diseases start in rodents, animals such as monkeys and chimpanzees, birds, and even bats, and then “jump” into humans. SARS may well have originated in bats.
Ebola, too
, probably existed as a virus in bats before emerging as a human disease in the mid 1990s. Shocking scenes of the 2014–2015 Ebola epidemic in West Africa were shown by the media, as were the incredible efforts of local and international teams to stop the outbreak. With no vaccine or cure available, thousands of lives were saved by determined healthcare workers who wore protective gear (rather like spacesuits) and tended those affected. Eventually this frightening and lethal disease was brought to a halt, but scientists are now constantly on the lookout to detect any future outbreaks quickly while they continue to search for a vaccine or cure. And, of course, security in all research laboratories is very high, because of the danger of such viruses and the risk that they could fall into the wrong hands and be used as biological weapons.
Attention has also been focused on diseases transmitted by the bite of infected mosquitoes. Zika virus was first identified in the 1940s in the Zika Forest in Africa but it was only more recently, when major outbreaks occurred in a number of countries across the globe, that serious concern was raised about its potential risks. As with Ebola, there is as yet no known cure: taking sensible precautions—in particular avoiding certain regions and protecting against mosquito bites—is so far the only way to avoid getting Zika virus.
Let’s not forget the old and neglected tropical diseases
There are many severe and, indeed, ancient diseases of the subtropical and tropical world. In parts of Africa, in spite of optimistic progress in recent decades, every minute or so a child dies of yet another mosquito-borne disease: malaria. Other, less well-known, diseases are now called “neglected tropical diseases.” Some are spread by insects, some by contaminated water, and some are linked to parasitic worms that live inside the human body. These can not only lead to premature deaths but can also cause long-term damage, including malnutrition, stunted growth, and poor educational attainment in children. Unlike pandemics that threaten the whole world, these diseases—linked, among other things, to poverty, hunger, war, climate change, polluted and insanitary environments, and proximity to disease-carrying animals, birds, and insects—are not often headline news but nevertheless deserve attention, as they affect the most vulnerable people on the planet who often have limited access to modern medicines and healthcare.