This article, Watch 62 Years of Global Warming in 13 Seconds, is syndicated from Climate Central and is posted here with permission.
From our friends at NASA comes this amazing 13-second animation that depicts how temperatures around the globe have warmed since 1950. You’ll note an acceleration of the temperature trend in the late 1970s as greenhouse gas emissions from energy production increased worldwide and clean air laws reduced emissions of pollutants that had a cooling effect on the climate, and thus were masking some of the global warming signal.

The data come from NASA’s Goddard Institute for Space Studies in New York (GISS), which monitors global surface temperatures. As NASA notes, “All 10 of the warmest years in the GISS analysis have occurred since 1998, continuing a trend of temperatures well above the mid-20th century average.”

Related :

131 Years of Global Warming in 26 Seconds
2012 Global Temps Rank in Top 10 Hottest on Record
NOAA: 2012 Hottest and 2nd-Most Extreme Year On Record
5 Must-See Charts From Major New U.S. Climate Report
Forget the Melting Arctic, Sea Ice in Antarctica is Growing

Advertisements
Approaching a Mass Extinction? (via Climate Central)

By Alyson Kenward The Golden Toad, native to Costa Rica, is believed to have gone extinct in 2007. A new study suggests Earth may be on the verge of mass extinction. Credit: Wikimedia

Three Things You Should Know:

1) During the past couple hundred years, scientists have documented the extinction of more than 700 animal species — and this is probably just a small fraction of the total number of modern plant and animal extinctions.

2) By comparing the rate of extinction today to previous rates revealed by fossil records, scientists project that the Earth may soon experience “mass extinction”, the likes of which have only occurred five other times in about 540 million years.

3) Human activities like hunting, deforestation, agricultural development, and pollution have caused many modern extinctions and climate change also poses a significant threat. Depending on the rate of global warming, researchers predict 20-35 percent of today’s species may be lost forever during the next several centuries.

The Debrief:

Several news outlets ran a story earlier this week about research that finds the rate of plant and animal extinctions around the world today is much higher than during most periods of history. In fact, the research says extinctions are currently so common that Earth may be on the verge of a “mass extinction.”

Paleontologists have only documented five other periods of mass extinction in history, when fossil clues indicate that as much as 75 percent of species were wiped out over periods of a few thousand to a couple million years.

Scientists today have recorded a staggering number of extinctions in just the past two centuries — including more than 700 mammals, reptiles, and bird species. But because biologists know they haven’t come anywhere close to discovering all the species on Earth, that figure is probably just a tiny fraction of the real number of extinctions that are taking place. With that in mind, researchers at the University of California at Berkeley compared the current extinction rate to rates recorded in the fossil record. They found that what is happening these days is completely out of the ordinary.

In particular, the rates at which mammals, birds, and reptiles are going extinct today is as fast — and in some cases, much faster — than what led to the five major extinctions in the past. The study is published in the March 3 issue of Nature.

To date, only a small percentage of species have been lost in modern times, which means this era doesn’t yet qualify as a “mass extinction.” But what is important, write the study’s authors, is how rapid the recent extinctions appear to be taking place. If the rate of species loss continues, and if many critically endangered species, like southern bluefin tuna or mountain gorillas, disappear, they say it would “propel the world to a state of mass extinction.”

In other words, we’re not experiencing this kind of event right now…but we may be on the cusp.

Why This Science Matters:

Past mass extinction events had a number of likely causes. Periods of dramatic climate change, when the planet was quickly warming or cooling, have been implicated in many of these events. In addition, rising concentrations of greenhouse gases, including carbon dioxide (CO2), changed the ocean’s chemistry so drastically at times that most species couldn’t survive. And asteroid collisions probably instigated at least one of the mass extinctions.

We’re not expecting another asteroid collision anytime soon, but some of the other triggers — climbing temperatures and ocean acidification — are taking place today.

Of course, there is one very big difference between prior times of mass extinctions, and now: us. Humans weren’t around during any of the previous extinctions, so it would be tempting to think that today’s extinctions are unrelated to human behavior. But according to this study and other research, that clearly isn’t the case.

Pollution, hunting, clear-cutting vast swaths of rainforest; all these human activities have contributed to the loss of hundreds of species. Recent climate change, which is likely caused in part by burning fossil fuels, have also begun to put pressure on species the world over, and further climate change will likely put even more species at risk.

In fact, computer models predict that if global warming continues in the coming decades, between 20 and 35 percent of the planet’s species could be headed for extinction within just 40 years.

Plot showing the variations, and relative stab...

Plot showing the variations, and relative stability, of climate during the last 12000 years. (Photo credit: Wikipedia)

Scientists Find an Abrupt Warm Jog After a Very Long Cooling

By ANDREW C. REVKIN (Dot Earth) March 9

There’s long been a general picture of the climate of the Holocene, the period of Earth history since the last ice age ended around 12,000 years ago. It goes like this: After a sharp stuttery warm-up following that big chill — to temperatures warmer than today — the climate cools, with the decline reaching bottom around 200 years ago in the period widely called the “little ice age.” (A graph produced by Robert Rohde for his Global Warming Art Web site years ago nicely captures the general picture.)

A new Science paper includes this graph of data providing clues to past global temperature. It shows the warming as the last ice age ended (left), a period when temperatures were warmer than today, a cooling starting 5,000 years ago and an abrupt warming in the last 100 years.
Science A new Science paper includes this graph of data providing clues to past global temperature. It shows the warming as the last ice age ended (left), a period when temperatures were warmer than today, a cooling starting 5,000 years ago and an abrupt warming in the last 100 years.

In a new study, researchers from Oregon State University and Harvard have analyzed 11,300 years of data from 73 sites around the world and added more detail to this picture. The work, posted online today, is being published Friday in the journal Science.

While the researchers, conclude that the globe’s current average temperature has not exceeded the warmth that persisted for thousands of years after the last ice age ended, they say it will do so in this century under almost every postulated scenario for greenhouse gas emissions.

In a news release, Candace Major, program director for ocean sciences at the National Science Foundation, which paid for the research, said:

The last century stands out as the anomaly in this record of global temperature since the end of the last ice age…. This research shows that we’ve experienced almost the same range of temperature change since the beginning of the industrial revolution as over the previous 11,000 years of Earth history – but this change happened a lot more quickly.

In sum, the work reveals a fresh, and very long, climate “hockey stick.”

The hockey stick climate analogy arose from a variety of studies of the last millennium or two of temperatures in the Northern Hemisphere, Arctic and planet. There’s a general pattern of a sharp warming from the 20th century onward. The shaft of the “stick” has a lot of wiggles and warps and still comes with substantial uncertainty, but the general pattern is well established. The Wikipedia entry is a reasonable starting point for reviewing varied views of this body of science.

 

While folks have long talked of “abrupt climate change” (as in NRC reports) as a plausible prospect, this paper builds on the idea that we’ve been in the midst of abrupt climate change since the early 20th century.

%d bloggers like this: