How do we protect our young from ourselves?

"The old are eating the young," wrote Satyajit Das, in a stark warning. Today's prosperity is based on debt as people consume more than the earth can sustain. "A significant proportion of recent economic growth has relied on borrowed money -- today standing at a dizzying 325% of global gross domestic product. Debt allows society to accelerate consumption, as borrowings are used to purchase something today against the promise of future repayment." We are degrading the environment and fossil fuels are resulting in global warming. A few weeks back the US withdrew from the Paris climate accord, prompting a ferocious reaction from opponents who say that China is a winner. Is it? "Trump's coal bet faces Moore's Law," wrote Prof Stephen Mihm. In 1965, Gordon Moore found that the number of transistors per integrated circuit doubled, with an increase in speed, about every two years, while costs went down. However, some technologies, such as chemicals and household goods, do not follow Moore's Law, while energy "is a mixed bag". Adjusting for inflation coal costs the same as it did in 1890, while the price of solar power is dropping by 10% per year, so that solar will be competitive with coal by 2024. It will make sense for companies to shift to renewable energy. Prof Rohit Prasad uses game theory to try to explain if Trump's exit is a "masterstroke, death knell, or farce". If everyone switches to more expensive energy sources while the US uses cheap coal it will get an advantage in international trade, unless other nations can exact some cost as punishment from the US. They cannot because the Paris accord in not binding on any nation so the US could have just carried on polluting as before. Therefore, Trump's gesture is an empty one. Is it? If there is nothing to lose and if renewable energy is inevitable then Trump has pleased his political supporters at no cost whatsoever. That makes it a masterstroke. As birthrates fall and the number of retired people increases it is going to impose an increasing economic burden on the young. "In 1970, in the US, there were 5.3 workers for every retired person. By 2010 this had fallen to 4.5, and it's expected to decline to 2.6 by 2050. In Germany, the number of workers per retiree will decrease to 1.6 in 2050, down from 4.1 in 1970. In Japan, the oldest society to have ever existed, the ratio will decrease to 1.2 in 2050, from 8.5 in 1970," wrote Das. According to a report from the World Economic Forum, the savings gap for pensions in just 8 countries in the world will be an eye-watering $400 trillion. It will be worse if people live longer. The only solution to the problem is to reduce the number of people so that earth's resources can pay for everyone. How to do that is the question.