Showing posts from April, 2017

Atmospheric CO2 Passed Important Threshold

The Earth just reached a CO2 level not seen in 3 million years The last time Earth had comparable levels of atmospheric carbon dioxide was about three million years ago, during the mid-Pliocene. Back then, global average temperature was about 3.6–5.2°F (2–3°C) warmer than it is today. Sea levels were also higher, by about 15–25 meters. And while passing 400 parts per million permanently — or hitting a high of 410 parts per million, as happened on Tuesday — won’t trigger any immediate climate consequences, it is a stark reminder of the profound influence human activity is having on the planet. That's sea levels higher by 50 to 80 feet.  And a 3 degree Celsius increase doesn't sound like much but it means a very different planet than we are now experiencing.

Certainly now we are undergoing some droughts, floods, and extreme weather, and some social breakdown.  But at 3 degrees Celsius we can expect far more serious consequences of this kind.

As you can see that CO2 curve is ac…

Florida's Nightmare Scenario

The Nightmare Scenario for Florida’s Coastal Homeowners  I've posted about Florida before, here and here, for example.  And now some more details about how the catastrophe will come about. When Cason first started worrying about sea-level rise, he asked his staff to count not just how much coastline the city had (47 miles) or value of the property along that coast ($3.5 billion). He also told them to find out how many boats dock inland from the bridges that span the city’s canals (302). What matters, he guessed, will be the first time a mast fails to clear the bottom of one of those bridges because the water level had risen too far. “These boats are going to be the canary in the mine,” said Cason, who became mayor in 2011 after retiring from the U.S. foreign service. “When the boats can’t go out, the property values go down.” Once the fall in prices begins, the decline will be precipitous.  There will be no opportunity to wait for better times.  They will be stuck with worthless p…

Climate Change: It's Rate Of Change

I've posted about this before, it's the rate of change in the concentration of carbon dioxide in the atmosphere not the level, that matters.  If the CO2 increases slowly, the planet is able to make an adjustment, but when it accelerates it can't.

Skeptical Science makes the same point but with graphics.

For 1 million years life on earth has adapted itself to going into and out of ice ages over approximately 100,000-year cycles. We come out of ice ages in about 10,000 years, with CO2 rising 100 ppm in that time. That is a rate of increase of about 0.01 ppm/year. If we use this as a typical rate to which nature has adapted, and has done so already for at least 10 cycles, then we can determine how much faster than this we are now moving. The idea is that if we limit CO2 rise to this rate, we expect nature will adapt; the further away we move from this base rate the more difficulty nature will have adapting. Even before the age of big oil and coal, we were already pushing nat…

The Climate System Is An Angry Beast

If we keep burning lots of fossil fuels, we could soon cause higher carbon dioxide levels and faster climate change than the Earth has seen in 50 million years. If we burn all available fossil fuel reserves, we’ll see faster climate change than in the entire 420 million year record.

In particular, as shown in the first chart above, Earth’s climate has been fairly stable over the past several million years. The wiggles in the blue line represent transitions in and out of ice ages, due to wobbles in the Earth’s orbit around the sun, amplified by changes in the amount of carbon dioxide in the atmosphere (these are known as Milankovich cycles). The bottom frame in the chart shows the change in forcing (global energy imbalance) caused by the combination of changes in solar activity and the greenhouse effect. When the line is flat, the Earth’s energy balance is stable, and thus so is its climate. When there’s a steep change, something is upsetting that balance and causing a rapid climate ch…

A New El Nino On Its Way

In an unusual quick turn-around, a new El Nino appears to be on its way.  This has consequences for the Pacific Northwest, mainly more moisture, a lot more snow in next winter, and probably a very hot 2018.

The El Nino's are producing warmer years each time it occurs.
The strong El Niño of 2015-16 contributed to those years’ being the two warmest on record. So look forward to an even hotter 2018-19.

It's also unusual for one to appear so quickly after the last one.  This is clearly another consequence of climate change.  We are going to have to look forward to hotter, and more frequent El Nino's.

It could bring the drought back to California.  While recent heavy rains filled their reservoirs, their aquifers have been severely depleted in the last drought as people siphoned up the water because of the drought, but the recent rains haven't replenished them.  So another drought would be a lot more serious.

In the Pacific Northwest we'll have more rain and snow, but …

A Critical Tipping Point Awaits Us

For millions of years out atmosphere has had just enough CO2 to permit life on this planet to prosper. Without CO2 our atmospheric temperature our planet would be a snowball.  With CO2 we have a global temperature that has brought us the bounty of life that has existed over eons.

But too much of it can be a problem as well.  I have posted about this, here and here.

How much danger are we in?  The consequences of the CO2 we are pouring into the atmosphere are direindeed.  But we may have more to worry about than just what human activity is causing.  There are large reservoirs of CO2 and methane held in soil and in the sea.  But these reservoirs of greenhouse gases are in great danger of being released.
As global warmingthaws the permafrost, the frozen land that covers nearly six million square miles of the earth, a big question for scientists is: How much will be lost?
The answer, according to a new analysis: more than many of them thought.  A study published Tuesday in the journal N…

Quantifying The Risk Of Climate Change

It's possible to quantify the risk to our planet from climate change.  And it doesn't look good for civilization.  (h/t Alternet)

Human activities now rival the great forces of nature in driving changes to the Earth System (Steffen et al., 2007). This has led to the proposal that Earth has entered a new geological epoch – the Anthropocene (Crutzen, 2002; Crutzen and Stoermer, 2000).  [....]
For biodiversity, typical rates of background extinction are estimated to be around 0.1 extinctions/million species years (De Vos et al., 2015). Current extinction rates are estimated to be tens to hundreds of times higher than natural background rates of extinction (Barnosky et al., 2012; Ceballos et al., 2015). Humans have now modified the structure and functioning of the biosphere to such an extent that the Anthropocene may mark the beginning of a third stage in the evolution of Earth’s biosphere, following the microbial stage from ~3.5 Ga BP and the metazoan from ~650 Ma (Williams et al…

Geoengineering May Be The Solution To Global Warming

Especially with the current U.S. Administration have gutted American response to global warming, people who are paying attention are getting very worried.

To Curb Global Warming, Science Fiction May Become Fact News about the climate has become alarming over the last few months. In December, startled scientists revealed that temperatures in some parts of the Arctic had spiked more than 35 degrees Fahrenheit above their historical averages. In March, others reported that sea ice in the Arctic had dropped to its lowest level on record. A warming ocean has already killed large chunks of Australia’s Great Barrier Reef. Let’s get real. The odds that these processes could be slowed, let alone stopped, by deploying more solar panels and wind turbines seemed unrealistic even before President Trump’s election. It is even less likely now that Mr. Trump has gone to work undermining President Barack Obama’s strategy to reduce greenhouse gas emissions. .
The world is not cutting emissions fast …

Greenland Ice Past Tipping Point

Ice caps and glaciers along the coast of Greenland passed a tipping point in 1997, when a layer of snow that once absorbed summer meltwater became fully saturated. Since then, the coastal ice fields—separate from the main Greenland Ice Sheet—have been melting three times faster than they had been, according to a new study published Friday in the journal Nature Communications."The melting ice caps are an alarm signal for the ice sheet. It means long-term ice mass loss is inevitable. It will increase and accelerate if nothing changes," said lead author Brice Noël, a scientist at the  University of Utrecht Institute for Marine and Atmospheric Research. "It's very unlikely the ice caps will recover. It's a climate tipping point—the time at which a change or an effect cannot be stopped."Climate scientists are wary of tipping points, when a series of small changes make a much larger change inevitable. The fear is a total meltdown of the Greenland Ice Sheet, which…