Bill Gates writes in the article kindly submitted here, after giving some examples of inventions, "Thanks to inventions like these, life has steadily gotten better. It can be easy to conclude otherwise—as I write this essay, more than 100,000 people have died in a civil war in Syria, and big problems like climate change are bearing down on us with no simple solution in sight. But if you take the long view, by almost any measure of progress we are living in history’s greatest era. Wars are becoming less frequent. Life expectancy has more than doubled in the past century. More children than ever are going to primary school. The world is better than it has ever been."

And that is correct. I'll focus on the huge increase in life expectancy, since that is often discussed here on HN. The low-hanging fruit of increasing life expectancy is increasing it for young people, by reducing infant and child mortality. The Gates Foundation does a lot of work in developing and delivering vaccines to protect children against infectious diseases. That means mothers can be more sure of their children surviving infancy, and all over the world (as other comments here have already pointed out), that results in a "demographic transition," of families eventually having dramatically fewer children. Children who grow up healthy and survive to adulthood do a lot to transform societies from backwardness into development and innovation.

The increases in lifespan are occurring at the old end of the lifespan too.[1] (This is a point that is often specifically denied in HN discussions, so I thought I should draw attention to it here.) Life expectancy at age 40, at age 60, and at even higher ages is still rising throughout the developed countries of the world. The increase in lifespan in developed countries has been so steady for so long that a girl born in the developed world since the year 2000 has a better than even chance of celebrating her 100th birthday, with boys likely to live almost as long.[2] And this comes from steady, incremental progress in the prevention and treatment of disease and the maintenance of good general health, not at all from any path-breaking research in "life extension." This suggests that similar day-by-day improvements in human life can come about from simple, barely noticed better practice replacing former haphazard practice. The programmers who Bill Gates encourages to join in on solving problems of the world may be able to harness computer power to notice patterns in data that may improve health and longevity, environmental quality, recycling of natural resources, and a variety of other important aspects of human life little by little all over the world.

I read The Limits to Growth when I was a kid, soon after the book was published. It was the most spectacularly factually incorrect set of predictions of all the predictions of the future I have ever read. I think Bill Gates here is writing based on a better understanding of how the world works, and I expect when my daughter has her 100th birthday in the twenty-second century that she will enjoy a world almost unimaginably better for almost all people than the world we share today.

[1] http://www.scientificamerican.com/article.cfm?id=longevity-w...

[2] http://www.demographic-challenge.com/files/downloads/2eb51e2...

http://www.prb.org/Journalists/Webcasts/2010/humanlongevity....