The Paris Agreement, which delegates from 196 countries hammered out in December 2015, calls for holding the ongoing rise in global average temperature to 'well below 2 °C above pre-industrial levels,' while 'pursuing efforts to limit the temperature increase to 1.5 °C.' How much difference could that half-degree of wiggle room (or 0.9 degree on the Fahrenheit scale) possibly make in the real world? Quite a bit, it appears.
The European Geosciences Union published a study in April 2016 that examined the impact of a 1.5 degree Celsius vs. a 2.0 C temperature increase by the end of the century, given what we know so far about how climate works. It found that the jump from 1.5 to 2 degrees—a third more of an increase—raises the impact by about that same fraction, very roughly, on most of the phenomena the study covered. Heat waves would last around a third longer, rain storms would be about a third more intense, the increase in sea level would be approximately that much higher and the percentage of tropical coral reefs at risk of severe degradation would be roughly that much greater.
4.0 out of 5 stars good but not great. Some excellent tunes and interesting soundscapes particularly towards the end of the album with Secret and Intensify part 1. Another word for intensified. Find more ways to say intensified, along with related words, antonyms and example phrases at Thesaurus.com, the world's most trusted free thesaurus.
But in some cases, that extra increase in temperature makes things much more dire. At 1.5 C, the study found that tropical coral reefs stand a chance of adapting and reversing a portion of their die-off in the last half of the century. But at 2 C, the chance of recovery vanishes. Tropical corals are virtually wiped out by the year 2100.
With a 1.5 C rise in temperature, the Mediterranean area is forecast to have about 9 percent less fresh water available. At 2 C, that water deficit nearly doubles. So does the decrease in wheat and maize harvest in the tropics.
On a global scale, production of wheat and soy is forecast to increase with a 1.5 C temperature rise, partly because warming is favorable for farming in higher latitudes and partly because the added carbon dioxide in the atmosphere, which is largely responsible for the temperature increase, is thought to have a fertilization effect. But at 2 C, that advantage plummets by 700 percent for soy and disappears entirely for wheat.
Three climate scientists at NASA's Jet Propulsion Laboratory, who were not involved with this study, shed some light on the study's results, starting with the impact on agriculture.
Corn plants with no corn
Why does a half degree of temperature increase make such a difference to some of the crops that were studied? For one thing, a half degree averaged out over the whole world can mean much more of an increase in some locations and at certain times.
'Most of that temperature change may occur during a small fraction of the year, when it actually represents conditions that could be 5 or 10 degrees warmer than pre-industrial temperatures instead of just 1.5 or 2 degrees warmer,' said Dave Schimel, who supervises JPL's Carbon Cycle and Ecosystems group.
And Schimel pointed out that heat can imperil agriculture even when crops don't die. 'If you get really high temperatures or very dry conditions during critical parts of the development of the crop, it produces essentially no grain. For example, above certain temperature thresholds, corn doesn't die but it doesn't grow seed. It doesn't grow a corncob. And other crops are similar to that, where the development of the actual food part of the crop is dramatically inhibited above critical temperatures.'
But what about that fertilization effect from carbon dioxide? 'It does help a bit, but it doesn't make the underlying problem go away,' he said. 'And by the way, if the plant was growing really fast when it died, it still died.'
Can we avoid the extra half-percent temperature increase? Schimel agrees that we should try hard to do so, but cautions that we don't know how to fine-tune global warming with that much precision. 'If we aim for 2 degrees, we might hit 3 degrees,' he said. 'If we aim for 1.5 degrees, we might still hit 2 degrees.'
A multi-century commitment
Felix Landerer, who studies sea level and ice at JPL, said timescale is critical to forecasting how high the ocean will rise.
'This paper looks at this century,' he said. 'So the effects appear to be fairly linear.' That is, a third more increase in temperature produces about a third more increase in sea level.
'But,' he said, 'I would frame the discussion in the context that in recent studies—in particular of ocean-ice interactions—there is growing concern that the ice sheets are very sensitive to the surrounding ocean warming.' These studies show that giant glaciers in Greenland and Antarctica melt not only from the top down, but also from the bottom up as relatively warm ocean water makes its way to their undersides.
'At two degrees (of temperature increase),' he said, 'you might have crossed a threshold for significantly more sea-level rise than indicated here.' In other words, even if we are able to limit the rise in global air temperature to 2 degrees Celsius by the end of the century and stop the increase at that point, the ocean holds so much heat that it can continue melting ice sheets and thus raising sea level far beyond that point in time.
'The air temperatures level off, you (hypothetically) stabilize them, but you have committed to sea-level rise over multiple centuries,' Landerer said. 'So it's good to stay away from two degrees. That's an experiment you don't want to run. Because that experiment would potentially wipe Florida off the map.'
Generations down the road
The EGU study found that the difference between 1.5 and 2 degrees Celsius of warming 'is likely to be decisive for the future of tropical coral reefs.' JPL's Michelle Gierach was not surprised.
Intensify 1 0 4 Equals
'Reef-building corals are extremely vulnerable to warming,' she said. 'Prolonged warming harms warm-water corals not only through bleaching (a phenomenon in which corals under stress, such as from water that is too warm, expel the algae they need to survive), but also through making them more susceptible to disease.'
Gierach attended the international conference that produced the Paris Agreement and she was happy to see the ocean and climate getting their due attention. But she acknowledges the difficulty in turning that attention into action over a long period of time.
An unusually busy Atlantic hurricane season is showing no signs of letting up.
Hurricane Delta is currently churning toward the Gulf Coast, expected to make landfall in Louisiana later today. Delta is the 25th named storm this season and the ninth hurricane.
It's the earliest in the year that any season has reached 25 storms.
Delta is also the third storm this year to achieve 'major hurricane' status—that is, Category 3 or higher. Delta reached Category 4 status Tuesday night before weakening as it moved over Mexico's Yucatán Peninsula.
Macscan 2 8 ubk download free. An average Atlantic hurricane season sees only 12 named storms, six of which typically become hurricanes and three of which grow into major hurricanes.
This year's season already has exceeded two of those thresholds. And hurricane season doesn't end until Nov. 30.
According to NOAA's hurricane records, the 2020 season is inching closer to a record-breaking year.
The only year known to produce more Atlantic storms was 2005, which saw 27 named tropical storms and hurricanes and one unnamed subtropical storm. With nearly two months left in the season, it's possible 2020 could break the record for total number of storms.
The unusually busy season, and the possibility of a record-breaking year, raises the question of whether climate change is playing a role.
This year, a number of weather factors lined up to produce favorable conditions for hurricanes in the Atlantic (Climatewire, Aug. 21). Ocean temperatures were unusually warm for much of the year. Low sea-level pressure and favorable wind conditions also helped.
In general, though, climate change isn't expected to have much of an effect on the total number of hurricanes that form each year. Instead, it's likely to affect how strong those hurricanes get.
Numerous studies suggest that hurricanes will grow more intense as the climate warms. That means the total number of storms might not change all that much in the future—but a greater proportion of those storms will turn into major hurricanes. Nbm lp songs download.
It's an important distinction. The vice presidential debate on Wednesday demonstrated that politicians may distort the science of hurricanes for political purposes.
During the debate, moderator Susan Page asked Vice President Mike Pence whether he believes the science that suggests hurricanes are becoming wetter, slower and more damaging. (Multiple studies have concluded that climate change affects all of these characteristics in hurricanes.)
Pence responded that 'there are no more hurricanes today than there were 100 years ago.'
He then suggested that climate alarmists use hurricanes as means of advancing their own interests in a Green New Deal.
Acorn 6 3 – bitmap image editor photoshop. But Pence's answer sidesteps the actual science about climate change.
The latest research suggests that climate change isn't having a big impact on the frequency of hurricanes.
Rather, the storms themselves are changing. And research including a study appearing in Proceedings of the National Academy of Sciences in May shows that hurricanes are already growing stronger, as well as moving more slowly and dumping more rain.
And, as the Earth continues to warm, hurricanes are expected to intensify even more.
That's not all. Climate change not only affects how strong a storm becomes. Rhinoceros 5 2 – versatile 3d modeler. Online editing software like photoshop. It also affects how quickly a storm intensifies.
Hurricane Delta may be a record-breaker on that front. The Weather Channel reported that Delta is believed to be the fastest storm to spin up from a tropical depression into a Category 4 hurricane. It made the transition in just 36 hours.
That makes it one of the fastest-intensifying storms on record.
Studies suggest that climate change will increase the speed at which hurricanes intensify over the ocean. Some research indicates that rapid intensification events are already happening more frequently in some parts of the Atlantic (Climatewire, Aug. 26).
More research is needed to determine whether climate change played a role in Delta's intensification. But in general, it is the kind of event that scientists expect to happen more frequently as the planet continues to warm.
So the 2020 hurricane season is unusual in several regards—a record-breaker on some fronts, and nearing a record on others.
While the number of storms is remarkable, it's important to keep that figure in perspective—especially as hurricanes and climate change shift into the election spotlight. From a climate change angle, the strength of the storm is what counts.
Intensify 1 0 4 +
Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.
