This summer's extreme weather could be a sign that potentially deadly climate change is already underway, according to scientists quoted by The New York Times. Experts are hesitant to blame global warming for individual events, such as the recent heat wave in the U.S., or fires in Russia, or Pakistan's devastating floods. But they say these disasters are examples of extremes — what Times columnist Thomas Friedman calls "global weirding" — that may already be occurring more frequently as the world grows hotter. Has this summer's heat made global warming undeniable? (Watch a Sky News report about the weird weather)

Consider this summer's weather a warning: Climate change skeptics mocked people concerned about global warming during the winter's "Snowmageddon" storms, say the editors of The Washington Post, but they're not laughing any more. The catastrophes in Russia and Pakistan, a fifth of which is now under water, may not have been triggered by global warming, but they are examples of how higher temperatures make all kids of "dangerous weather events" far "more destructive." This is a preview of the price we'll pay if we continue "to pump carbon into Earth's atmosphere."
"A summer's warning"

Don't listen to the "alarmists": The global warming "alarmists" are "trying to scare the world into throwing away hundreds of billions of dollars in a fruitless effort to control the temperature of the Earth," says Walter Cunningham in the Houston Chronicle. But anyone who has really examined the data knows that man-made carbon emissions don't rule the climate — "the sun, oceans, and variations in the Earth's orbit" do. "Human-caused global warming is simply not a threat to be concerned about."
"Climate change alarmists ignore scientific methods"

The evidence is getting hard to dismiss: "I have long been something of a climate-change sceptic," says Michael Hanlon in Britain's Daily Mail, "but my views in recent years have shifted." Nowhere is the evidence harder to deny than in Greenland, where the huge ice sheet that covers 90 percent of the country "appears to be cracking up before our eyes." The melting of Arctic ice may be "the beginning of the end; the first concrete sign that the stability upon which our civilization depends is about to crumble into an overheated future."
"The crack in the roof of the world: 'Yes, global warming is real — and deeply worrying'"