Humanity faces a major problem (what I refer to here simply as the Problem) this century. And given the nature of the Problem it will most likely be a significant problem for all future generations as well, unless we seriously tackle this problem.
The Problem is one of the most significant problems we have ever faced. Sadly not very many people realize how big of a problem the Problem is, and few believe there is anything we can do to remedy the Problem. Thus people do not pressure their governments to take action to address the Problem.
There is an extremely strong scientific consensus concerning the likelihood that the Problem will impose unprecedented levels of suffering, disease and disability on people in both rich and poor countries. Indeed this is a certainty if we do nothing to prevent the Problem. Furthermore, the Problem threatens to undermine the economic prosperity of all nations, rich and poor alike.
Humanity is collectively responsible for the Problem. Our actions, especially over the past century and half, have made the Problem the reality it is today. If we hadn't pursued the actions we did, the Problem would not exist. It's a "man-made problem", and the only way to fix it is with a "man-made solution".
Some claim we should just focus on "adaptation" to minimize the harms of the Problem. Those taking this position doubt we can do anything to directly alter the certainty and severity of the problem. And yet many of the scientists with expertise on the nature of the Problem believe we can directly manipulate the factors responsible for the Problem. Numerous scientific experiments have demonstrated that the biological processes involved in senescence (aging) can be modulated, thus slowing down the rate of molecular and cellular decline. So if you hadn't yet guessed it, the Problem is GLOBAL AGING (what did you think it was?)
By the middle of this century there will be 2 billion people in the world over the age of 60. Most people over the age of 60 suffer from at least one serious medical condition, if not more. And they are a significant risk of co-morbidity. The number of people who die from age-related chronic disease each year is unprecedented. Never before in human history have so many humans died from such a slow and painful (and expensive) death.
Global aging is a product of human action. Civilization has become so successful at preventing early and mid-life mortality- thanks to public health measures like the sanitation revolution, immunizations, antibiotics, changes in behaviour and increases in material prosperity- that our populations now age. This was not the case for 99.9% of our species' existence. Life expectancy at birth for humans was 30 years or less for the vast majority of the time homo sapiens existed. Today it is age 70 for the world as a whole, and is expected to rise to age 80 by the end of the century.
While in many respects this is an incredible success story, it is also a story of the creation of a new and novel health challenge- the challenge of keeping our bodies and minds healthy beyond the biological warranty period (estimated to be approximately 70 years) that evolved from our life in hunter gather societies.
Given the rapid rise of chronic disease that has already occurred, and will dramatically rise this century as populations age, what can be done? The strategy of adaptation is one that simply takes the biology of aging we have inherited from our specie’s life and evolutionary history as a given, and looks for ways to minimize the harmful effects of aging. So promoting exercise, or tackling specific diseases of aging by funding medical research on cancer or Alzheimer’s disease, or redesigning cities to better promote the mobility of aging populations, raising the age of eligibility for social security, etc. these are all adaptive solutions. They are important, but of very limited impact. Eliminating all 200+ types of cancer would only likely increase life expectancy at birth by a few years (e.g. 3 years) because those most at risk of death by cancer (age >60) would simply die from one of the other major causes of age-related death, like a stroke or heart disease.
A more ambitious and rational strategy would be to aspire to modulate aging itself. Some humans naturally possess the ability to retard the normal rate of aging. Centenarians and supercentenarians (age > 110) possess “longevity genes” that delay and even insulate them from the more common health conditions that afflict the normal person decades earlier. I believe the development of a drug that activates the “anti-aging” genes these rare individuals naturally possess would be, by far, the most significant advancement in medicine this century. It would, at a minimum, simultaneously delay age-related frailty, disease and disability. It might also compress morbidity and mortality at the end of the lifespan, so that the period of time it takes to die once our health has faded is shorter than how we die under the normal rate of biological aging. Retarding human aging could dramatically increase the health span and reduce the period of time humans will suffer chronic disease. Such an intervention could be something all future generations benefit from as well. There are hardly any global problems as pressing and significant as tackling aging is today.