• The Nobel Prize for economics, the dismal science, went this year to an optimist: Angus Deaton, of Princeton University. His book, “The Great Escape,” is in large part fanfare for the common man and woman: They have done much better over the past century than they ever have before. As David Leonhardt, the editor of The Upshot at The New York Times wrote, Deaton’s book shows that “by the most meaningful measures — how long we live, how healthy and happy we are, how much we know — life has never been better. Just as important, it is continuing to improve.”

    It’s nice to read that, because it cuts against the trend in global punditry. Deaton’s book is like the song of the lark — the sweeter for rising, if only for a minute, above warnings of doom.

    Still, even for Deaton, it’s hardly all sunshine. His largest fear — global warming — has become so familiar that it’s easy to forget the sheer magnitude of its potential destruction. No, it’s not going to blow us up. But most scientists believe it could prove much more lethal to masses of people than any terrorist group has so far. A recent warning from the Committee of Concerned Scientists — and most scientists who work on the environment are concerned — put it starkly: “Unless we take immediate action to reduce global warming emissions, these impacts will continue to intensify, grow ever more costly and damaging, and increasingly affect the entire planet.”

    You may be able to live with — even if you are moved by — future flooding in far-flung parts of the world: But when New York City becomes regularly flooded in events like Hurricane Sandy (three years ago this month: 200 dead, $75 billion in damages), then sympathy will turn to horror.

    In Africa and parts of the Middle East (not to mention California), however, water is not everywhere but rather nowhere. Violent struggles over its availability are already evident, and will get worse. This isn’t a fear voiced by ranting liberal ecologists — it’s a truth acknowledged by the United States military.

    Jihadist terror, centered in but not confined to the Middle East, has nothing on that scale. But when the better-organized groups acquire weapons of mass destruction, we will witness a paradigm shift in their menace.  Already civil and religious wars are roaring through the Middle East, Afghanistan, Pakistan, India, the Caucasus — and terrorist outfits are probing into China, Europe and North America.

    Skeptics note that the leaders of jihadist groups are ignorant of the complexities of biological, chemical and nuclear weapon development. But since Islamic State is now estimated to earn $1.5 million per day from what the FT calls “minutely managed” oil production for which it “actively recruits skilled engineers,” it seems unlikely that it cannot attract skilled nuclear scientists, if the price is right.

    Can’t the United States, indispensable nation as it is, do something? Yes, it can and it does.But the United States’ military intervention against ISIS, as the group is also known, has failed to stem the militant group’s growth.

    While the United States remains the paramount global military power, its influence is erodingat a time when there is little world consensus on climate change and terrorism. Russia, among major powers, seems least disposed to common action: Its seizure of Crimea from Ukraine and its continued sponsoring of the rebellion in the country’s east have so weakened a state still mired in corruption that serious people now speak of another popular revolt.

    Strength seems more efficiently deployed by Russia (in spite of its economic decline) and growth is still high (relative to the rest of the world) in China, in spite of its slowdown. By contrast, crucial U.S. allies in the European Union now face continuing uncertainty in the common currency and a massive refugee crisis. These issues have fuelled fears that the union may dissolve back into separate nation states.

    Europeans have never had a great attachment to the European Commission and the European Parliament, other than taking advantage of the former’s largesse for national projects. National politics remain the focus of what loyalty there is to the democratic institutions in the EU – but even that is fading. The Economist noted that “between 1980 and 2000 the cause of democracy experienced only a few setbacks, but since 2000 there have been many. And democracy’s problems run deeper than mere numbers suggest. Many nominal democracies have slid towards autocracy, maintaining the outward appearance of democracy through elections, but without the rights and institutions that are equally important.”

    Even the threat of nuclear Armageddon, a relic of decades past, has reared its head again, as the U.S. and Russia race to modernize their nuclear forces. Sam Nunn, the U.S. senator and veteran nuclear disarmament activist, said earlier this year, “trust has been eroded to the point of almost being destroyed. You got a war going on right in the middle of Europe. You got a breakdown of the conventional forces treaty, you got the INF (Intermediate-Range Nuclear Forces) treaty under great strain, you got tactical nuclear weapons all over Europe. It’s a very dangerous situation.”

    We have not had, for nearly three decades, an existential threat held insistently over our heads. Now, even as the luckier of us live in what most of our grandparents would have seen as luxury, we have several. To live beyond these threats rather than die en masse because of them will take much more focus than we have wished to muster.