divulgatum está dedicado a la difusión de conocimiento científico en español e inglés, mediante artículos que tratan en detalle toda clase de temas fascinantes pero poco conocidos.
divulgatum is devoted to the dissemination of scientific knowledge in Spanish and English, through articles that go into the details of all sorts of fascinating, if not
widely known, subjects.

Sunday, January 22, 2017

The tipping point

The global problems that will define the twenty-first century are already taking form.

Overpopulation and the poor living conditions associated with it are already a major problem in many regions. (Credit: Alicia Nijdam/Wikipedia)

THE LAST HALF-CENTURY has brought what is perhaps the greatest transformation in our history. We now live in a world that our grandparents could never have imagined, where things like clean water, safe electricity, heating, cheap goods, effective medicines, fast transport, instant access to information, and political stability are taken for granted by billions of people. On the other hand, besides the age-old threats of discrimination, poverty, injustice, violence and inequality, the twenty-first century is to be shaped by novel challenges that are already beginning to loom before us. Humanity has been thrown into — or rather created — a global picture unlike any seen before; human populations have grown so large that our impact on the planet is now undeniable, and our expansion is only expected to accelerate. Although living standards have improved spectacularly (yet unequally), the effects of our industrialised lifestyle on this planet are not only unprecedented, but have already escaped our own control, as reflected by the seemingly unstoppable rise in atmospheric and sea temperatures. These two fundamental threats — overpopulation and climate change — will thus be the root of the major challenges facing the generations to come over this century.

Global overpopulation is a relatively new concept for our species. If mankind’s presence on Earth was nearly insignificant only some centuries ago, now populations around the globe are experiencing lightning-speed expansion, which often comes hand-in-hand with the invasion of every available natural habitat. It is expected that there will be more than eleven billion people living on this planet at the turn of the twenty-second century, compared to today’s seven billion. However, this change is expected to occur unequally, with the least developed countries bearing the weight of population explosion, while developed regions may witness their citizens grow older and numbers decline.

Rapid population growth has notable negative consequences on both society and the environment, resulting from the higher economic needs of larger families, increased levels of consumption and waste, and tighter competition for jobs, which in turn opens the door to poor working conditions and meagre salaries. Thus, many countries would surely enjoy higher living standards and faster development, were they able to lower their birth rates. Remarkable examples of this are South Korea and Taiwan, both of which have experienced sustained economic growth and improvements in quality of life over recent decades, following declines in birth rate.

The best way to prevent widespread poverty and the exhaustion of natural resources as a result of unsustainably large populations is to implement measures aimed to provide long-term access to contraceptive methods in developing countries around the globe, as well as to educate societies about the benefits of having less children, which often goes against cultural norms. This can be achieved by means of voluntary family-planning programmes, which inform societies and families and help to avoid unwanted pregnancies. Because the reasons for this kind of pregnancies include the lack of information and access to contraceptives, unfounded fears about side effects and adamant opposition from husbands and social or religious leaders, family-planning programmes should concentrate much of their effort in outreach tasks, directed towards shifting reactionary views about contraception and small families. This kind of intervention has repeatedly proved successful in field experiments, with increases in contraceptive use leading to lower birth rates, which in turn yielded long-term benefits such as better-educated children and improved economic perspectives for their families. Crucially, the education of women is just as important a factor as ready access to contraceptives, since educated women tend to stand up for their reproductive rights more resolutely, marry later and have less children. It is also imperative that family-planning programmes be directed toward informing families about their reproductive alternatives and offering them the possibility to use contraception, but without ever forcing them to do so. Freedom of choice is key for success.

Some, on the other hand, may consider that developed countries should be more concerned about their own demographic issues than about the future of populations in developing regions. However, widespread poverty and conflict arising from overpopulation will inevitably trigger large-scale migrations toward developed countries, putting the latter under huge socioeconomic stress. There can be no doubt that the future of developing nations will profoundly affect developed ones, as our world becomes ever more globalised.

The second unprecedented challenge lying ahead is mankind’s growing impact on our planet as a whole, best depicted by the currently escalating rise in temperatures around the globe. So novel is this challenge that climate scientists and activists have found it very hard to overcome scepticism about climate change — not to mention media manipulation by parties with commercial interests in fossil fuels. A largely celebrated step forward was the recent Paris Agreement, signed in December 2015 by the parties to the United Nations Framework Convention on Climate Change, which set the goal of keeping the global rise in temperature below 2°C above the temperatures measured before the Industrial Revolution. However, such an aim can no longer be achieved solely through a reduction in greenhouse-gas emissions; the solution is supposed to rely on the development and application, over the second half of this century, of ‘carbon capture and storage’ technologies, which are able to permanently remove carbon dioxide from the atmosphere. This kind of technology is not only still in development but, surprisingly, was not even discussed at the Paris meeting. In light of this, some have claimed that the Paris agreement is not a successful step toward tackling climate change, but rather a spectacular procrastination exercise: today, we wait for nonexisting technologies to be developed in the future and solve what is already one of the biggest threats to human populations worldwide. And we pat ourselves on the back for such an imaginary victory.

Bioenergy crops are a popular potential technique for removing dioxide carbon from the atmosphere. (Credit: L. Brian Stauffer/University of Illinois.)

The problem with carbon capture technologies is not just that they will require extensive development before becoming an effective tool against climate change, but that, in order to this, they will need to be applied on such a massive scale that their environmental and socioeconomic cost may turn astonishingly high. For instance, one popular potential technology is called ‘bioenergy with carbon capture and storage’. It is based on bioenergy crops: crops grown explicitly to extract carbon dioxide from the air naturally. The plants are then burnt to produce energy in power stations, and the resulting carbon dioxide is captured and stored (for example, in liquid form). This method sounds feasible in theory, unless we consider that, in order to achieve the goal of the Paris agreement, around six hundred billion tonnes of CO2 will have to be removed from the atmosphere before the end of this century. Trying to achieve this with bioenergy crops alone would require about one-third of the total arable land on Earth. However, given the present exponential rate of human population growth, the land demands of bioenergy crops will stand in the way of the imperative need for increased food production. Moreover, putting such an extent of land into bioenergetic use would imply the destruction of very large expanses of wild forest and the use of huge quantities of fertilizer, which would themselves entail a considerable carbon footprint. Thus, likelihood is that bioenergy crops will be an insufficient means of repressing the rise in atmospheric CO2 levels.

This does not mean that the idea of bioenergy crops (or any other proposed carbon capture technology) should be abandoned from the outset. It rather illustrates that these technologies need to be put into context now, before they are implemented, and that much work still needs to be done toward accurately assessing each option’s potential for carbon removal and its possible effects on societies and ecosystems.

One of the main hurdles in addressing future problems, such as the aforementioned, is the human tendency to subconsciously downplay both future risks and benefits, as opposed to more immediate ones. Hence, the costs of transitioning to a sustainable low-carbon economy seem much greater to us than the future costs of extreme change in weather patterns, destructive atmospheric events and rising sea levels, even when these costs include not only economic losses, but also war, misery and the disruption of billions of lives. Several psychological studies have demonstrated such a proclivity to emphasise short-term benefits over long-term ones, as well as to settle for the status quo, instead of actively working for a change. However, these aspects of human nature can be harnessed as a tool for shifting public opinion on imperative problems including overpopulation and climate change. For instance, parallels could be drawn between predicted future situations and present ones, such as the tensions produced by the ongoing large-scale migration of Middle Eastern refugees to European nations. People may then visualise the consequences of millions of people simultaneously fleeing from countries struck by overpopulation, widespread conflict, desertification or rising sea levels in the near future. Resistance to actively change our high-carbon economy into a low-carbon one can be overcome by committing to a near-future deadline by which this transition must be accomplished — thereby diminishing our relative perception of the associated costs by shifting them toward the future — and making low-carbon technologies, such as renewable energies and electric cars, the default rather than the alternative — thus harnessing people’s reluctance to change for the greater good.

Needless to say, the defining challenges of the twenty-first century will not be easily addressed, given their unparalleled complexity and colossal scale. The great accomplishments of science and engineering witnessed in recent times, including the exploration of space, fundamental discoveries in physics, the tailoring of novel super-materials, and the understanding of the molecular basis of life, all pale in comparison to those problems which are indeed truly difficult: social injustice, discrimination, poverty, violations of human rights, and the ceaseless ravaging of our own home world. Addressing such issues and their roots will not only demand unprecedented degrees of will and commitment from the world’s most developed nations, but also active cooperation and dialogue between these and developing countries, which are most imperilled. Collaboration between governments, scientists, policymakers, demographists, engineers, economists, non-profit organisations and others parties involved is doubtlessly warranted, if mankind as a whole is to have any chance of ending the twenty-first century better off than we have started it.

Special thanks are due to Isobelle Bolton for her invaluable help with composition.

Bongaarts, J. Slow down population growth. Nature (2016).
Williamson, P. Scrutinize CO2 removal methods. Nature (2016).
Fehr-Duda, H., Fehr, E. Game human nature. Nature (2016).