A pause or not a pause, that is the question.

andyextance:

With 2014 looking set to be the warmest year ever (possibly by some way) I’ve been wondering what position the people claiming “global warming has stopped” might retreat to. This neat tale hints at one possibility, and explains why it wouldn’t be a convincing argument.

Originally posted on Open Mind:

UPDATE: A new post at RealClimate is very relevant, and well worth the read.


One day, a new data set is released. The rumor runs rampant that it’s annual average global temperature since 1980.

artdat

Climate scientist “A” states that there is clearly a warming trend (shown by the red line), at an average rate of about 0.0139 deg.C/yr. She even computes the uncertainty in that trend estimate (using fancy statistics), and uses that to compute what’s called a “95% confidence interval” for the trend — the range in which we expect the true warming rate is 95% likely to be; it can be thought of as the “plausible range” for the warming rate. Since 95% confidence is the de facto standard in statistics (not universal, but by far the most common), nobody can fault her for that choice. The confidence interval is from 0.0098 to 0.0159 deg.C/yr. She also…

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United States and China reach landmark carbon emissions deal

andyextance:

The recent US-China climate deal seems to bode well for next December’s key talks: In case you missed it this is a good summary.

Originally posted on co2balance:

B

Barack Obama and Xi Jinping have agreed a deal on cutting emissions into the 2020s

The big news this morning is that the US and China have unveiled a “secretly negotiated deal” to reduce their greenhouse gas output, with China agreeing to cap emissions for the first time and the US committing to deep reductions by 2025. China, the biggest emitter of greenhouse gases in the world, has agreed to cap its emissions by 2030 or earlier if possible, and has also promised to increase its use of energy from zero-carbon sources to 20 per cent by 2030. The US has pledged to cut its emissions 26-28 per cent below 2005 levels by 2025.

Barack Obama said the deal was an “historic agreement”. China’s premier, Xi Jinping, said the US and China had agreed to make sure a global climate deal is reached in Paris next year.

  • Under the deal…

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Will anyone follow this route to low emission, low cost farming?

Ammonia fertiliser plays a crucial role in producing the food we need. Image credit: Allen (roadsidepictures) used via Flickr Creative Commons licence.

Ammonia fertiliser plays a crucial role in producing the food we need. Image credit: Allen (roadsidepictures) used via Flickr Creative Commons licence.

Can we make sure we make the most of the promising ideas people come up with to restrain and adapt to the changes we’re making to the climate? I’ve been considering this question thanks to a recent invention seeking to help cut increasing greenhouse gas emissions that arise from feeding the world’s growing population. Stuart Licht’s team at George Washington University in Washington, DC, has worked out how to make a key component of fertiliser – ammonia – that could eliminate emissions and minimise cost. In fact it’s an extension of a method that Stuart told me can also produce zero carbon cement, iron, bleach, magnesium, and capture CO2 directly from the atmosphere. So when will we see this amazing approach in use? I can’t tell you that – because Stuart has no plans to commercialise it.

I became aware of the new ammonia production system when Chemistry World asked me to cover it for them. Ammonia is a simple molecule, comprising only two elements, hydrogen and nitrogen. Humans have been using it in fertiliser since at least the early 19th century, when it was mined, both in mineral form and as bird guano, for delivery to farmers. That was necessary because although nitrogen is hugely abundant – it makes up four-fifths of Earth’s atmosphere – it’s equally as unreactive. Chemists often replace the air above the reactions in their flasks with pure nitrogen when they’re worried that oxygen will affect their results. That stability meant synthetic ammonia was at first elusive.

But in the early 20th century Fritz Haber and Carl Bosch found a way to overcome nitrogen’s reluctance to react. They could take nitrogen from the air, and bring it together with hydrogen gas in the presence of an osmium catalyst at very high pressures and temperatures. During the First World War ammonia’s other main application – as a basis for explosives – saw that ramped up to industrial scale. The Haber-Bosch process has provided fertilisers that have been crucial in feeding Earth’s growing population since then. But it comes with a downside: it requires huge amounts of energy – 2% of the entire world’s consumption – whose generation usually releases the greenhouse gas CO2. Read the rest of this entry »

There’s nothing quite like renewables: Natural gas production will not reduce future greenhouse gas emissions as hoped

andyextance:

Because burning natural gas produces less CO2 emissions in generating a certain amount of power than coal, it’s seen as a ‘bridging fuel’, a step to getting emissions down. However, a new study accounting for how tricky it is to close existing power plants suggests increasing use of natural gas is not reducing net emissions. Taken together with recent results showing that poor practice in fracking is contaminating groundwater, the case is growing in favour of pushing harder for renewables and – dare I say it – nuclear power to fight climate change. Read more about the latest findings on gas power in Jonathan Trinastic’s interesting post:

Originally posted on Goodnight Earth:

Appropriate and useful climate policy-making requires accurate and reliable data about the future.  Nowhere is this more important than when setting carbon emission standards and projecting percentages of each energy source to match energy needs (coal, natural gas, nuclear, renewables, etc.).  But projecting how emissions will change in the decades to come, say to meet the 2030 standards, is a tricky business.  In particular, natural gas has been touted as a ‘bridge’ to a low-carbon future with predictions that it would take over a share of energy production from coal and thereby reduce net emissions (natural gas has about a fourth of the greenhouse potential of coal, if you take away methane leaks in transportation pipes).

But is this really true?  Does the data back this up?  These are the key questions policymakers must know the answer to when deciding whether to promote natural gas expansion with subsidies, etc.  And it falls…

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The hope behind climate change: adaptation strategies for coastal regions

andyextance:

If you focus too narrowly on the negatives of climate change too much you might give up hope, or be tempted into denial. But humanity is actually remarkably good at solving its problems, and that’s cause for optimism. Put into a good mood by the Labor Day holiday Jonathan Trinastic argues just that, inspired by a Nature Climate Change paper on the development of strategies responding to coastal impacts. It’s a nice summary, definitely worth a read.

Originally posted on Goodnight Earth:

Figure courtesy of aeccglobal.com

Figure courtesy of aeccglobal.com

Happy Labor Day!  In honor of a day traditionally taken off (except for retail employees, unfortunately) to enjoy grilling and relaxing outside, I thought I’d discuss something a bit more upbeat.  Climate change research can often be gloomy.  It is a necessary gloom in the form of research indicating severe dangers ahead – sea level rise, temperature increases, more severe storms, etc. – if we do not take action, and it does us no good to turn our heads even if this type of emotional denialism is tempting and easy.  But a little commentary came out in Nature Climate Change last week that provides some hope.  The article summarizes IPCC reports and describes a model approach to figure out how to respond to climate change and, in particular, sea level rise along the coasts.  This type of information is important both to determine how we can respond…

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With climate change, uncertainty is no-one’s friend

This post has moved. Read it here.

For some reason, WordPress chose to publish this blog entry in July, meaning it appears out of sequence on the blog. I’ve now corrected the date, but that’s broken the original link. Please direct any annoyance at WordPress.

Unique and unnatural: modern warming from an historical viewpoint

A Roman altar with the Sun in its chariot on the left, and Vulcan, the god of fire and volcanoes on the right. The climate gods long favoured the Roman Empire, with wobbles in Earth's orbit credited for increasing the amount of solar energy falling on Earth at the time. Image copyright: Nick Thompson, used via Flickr Creative Commons License.

A Roman altar with the Sun in its chariot on the left, and Vulcan, the god of fire and volcanoes on the right. The climate gods long favoured the Roman Empire, with Earth’s orbital dance credited for increasing the amount of solar energy falling on Earth at the time. Image copyright: Nick Thompson, used via Flickr Creative Commons License.

Our climate has changed before. It’s something most of us realise and can agree on and, according to Skeptical Science, it’s currently the most used argument against human-caused warming. If such changes have happened naturally before, the argument goes, then surely today’s warming must also be natural. It’s an appealing idea, with an instinctively ‘right’ feel. Nature is so huge compared to us puny humans, how can we alter its course? The warming we’re measuring today must just be a natural fluctuation.

It’s such an appealing argument that at the beginning of the 20th century that’s just what many scientists thought – that humans couldn’t alter Earth’s climate. In the time since, our knowledge has come a long way. We’ve explored space, become able to build the electronics that are letting you read this, and climate science has likewise advanced and benefited from these advances.

So what do we know today that might convince the sceptical scientists of 115 years ago that we’re warming the planet? Recently, Richard Mallett, one of my Twitter friends who describes himself as sceptical about mainstream climate science, made a point that serves as an excellent test of our current knowledge:

Of the historical warmings he’s referring to, perhaps the least familiar is the Holocene, which is ironic, as the Holocene is now. It’s the current period of geological time that started at the end of the last ice age, 11,700 years ago. By 1900 scientists would have known the term, but they couldn’t explain why it wasn’t as icey as before.

Three variables of the Earth’s orbit—eccentricity, obliquity, and precession—affect global climate. Changes in eccentricity (the amount the orbit diverges from a perfect circle) vary the distance of Earth from the Sun. Changes in obliquity (tilt of Earth’s axis) vary the strength of the seasons. Precession (wobble in Earth’s axis) varies the timing of the seasons. For more complete descriptions, read Milutin Milankovitch: Orbital Variations Image credit: NASA/Robert Simmon.

Three variables of the Earth’s orbit—eccentricity, obliquity, and precession—affect global climate. Changes in eccentricity (the amount the orbit diverges from a perfect circle) vary the distance of Earth from the Sun. Changes in obliquity (tilt of Earth’s axis) vary the strength of the seasons. Precession (wobble in Earth’s axis) varies the timing of the seasons. For more complete descriptions, read Milutin Milankovitch: Orbital Variations. Image credit: NASA/Robert Simmon.

The explanation we have today comes thanks to the calculations Milutin Milanković worked out by hand between 1909 and 1941. Milutin showed that thanks to the gravitational pull of the Moon, Jupiter and Saturn, Earth’s orbit around the Sun varies in three ways. Over a cycle of roughly 96,000 years our path varies between more circular and more oval shapes. The other two ways come because Earth’s poles are slightly tilted relative to the Sun’s axis, which is why we have seasons. The angle of that tilt shifts over a roughly 41,000 year cycle. Earth also revolves around that tilted axis, like a spinning top does when it slows down, every 23,000 years.

Together these three cycles change how much of the Sun’s energy falls on and warms the Earth, in regular repeating patterns. Though that idea would be the subject of much controversy, by the 1960s data measured from cylinders of ancient ice and mud would resolve any doubt. The slow descent into ice ages and more abrupt warmings out of them – like the one that ushered in the Holocene – come from Earth’s shimmies in space. Read the rest of this entry »

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