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Tag Archives: CO2

How important are clouds to our climate?

Lucy Reading-Ikkanda/Quanta Magazine


The Quanta Magazine article, A World Without Clouds A state-of-the-art supercomputer simulation indicates that a feedback loop between global warming and cloud loss can push Earth’s climate past a disastrous tipping point in as little as a century by Natalie Wolchover (2/25/19), reports on recent finding published in Nature Geoscience.

Clouds currently cover about two-thirds of the planet at any moment. But computer simulations of clouds have begun to suggest that as the Earth warms, clouds become scarcer. With fewer white surfaces reflecting sunlight back to space, the Earth gets even warmer, leading to more cloud loss. This feedback loop causes warming to spiral out of control.

The simulation revealed a tipping point: a level of warming at which stratocumulus clouds break up altogether. The disappearance occurs when the concentration of CO2 in the simulated atmosphere reaches 1,200 parts per million — a level that fossil fuel burning could push us past in about a century, under “business-as-usual” emissions scenarios. In the simulation, when the tipping point is breached, Earth’s temperature soars 8 degrees Celsius, in addition to the 4 degrees of warming or more caused by the CO2 directly.

There is evidence that this may have happened in the past:

More data points surfaced in China, then Europe, then all over. A picture emerged of a brief, cataclysmic hot spell 56 million years ago, now known as the Paleocene-Eocene Thermal Maximum (PETM). After heat-trapping carbon leaked into the sky from an unknown source, the planet, which was already several degrees Celsius hotter than it is today, gained an additional 6 degrees.

Related posts on feedback loops:
How are beavers creating a climate feedback loop?
Greenland Ice, Changing Albedo, and a Feedback Loop
Oceans as a Heat Sink: Possible Feedback Loop
A Feedback Loop: The Alaska Tundra
Methane Bubbles – A Feedback Loop

Clinker is responsible for how much of CO2 emissions?

In 2016 clinker contributed almost 2 billion tonnes of CO2, about 7% of the world total. What is clinker? The BBC article Climate change: The massive CO2 emitter you may not know about by 

Cement is the source of about 8% of the world’s carbon dioxide (CO2) emissions,according to think tank Chatham House.

If the cement industry were a country, it would be the third largest emitter in the world – behind China and the US. It contributes more CO2 than aviation fuel (2.5%) and is not far behind the global agriculture business (12%).

Clinker accounts for about 90% of the CO2 emissions related to concrete and so 90% of the 8% of world CO2 from cement is due to clinker.  Historical data for world cement production can be found on the USGS page  Historical Statistics for Mineral and Material Commodities in the United States. For the last couple of years see the Cement Statistics can Information page.  The BBC article has another a couple of other nice graphs and a diagram with an explanation of how cement is made.

Which country emits the most CO2?

The country that emits the most CO2 depends on how it is measured. Our World in Data has a graph of annual share of CO2 emissions by country. By this measurement, a graph with the top 5 countries (China, U.S., India, Russia, & Germany) in 2016 was downloaded from Our World in Data.  In this case, China has been the largest contributor of CO2 since 2005.  In fact, in 2016 China emitted 10,295 million metric tons of CO2 compared to 5,240 million metric tons by the U.S.  On the other hand, from EIA data, in 2016 each person in China emitted 7.3 tons of CO2 compared to a person in the U.S. at 16.2 tons.  The EIA data dates back to 1980, and from 1980 to 2106 China emitted 177,547 million metric tones of CO2 compared to 197,176 for the U.S.  Which is more important, per person, current, or total historical emissions?  How does this create challenges in climate talks? Further analysis with other countries can be done with EIA data. Data can also be downloaded from the Our World in Data post.  The Calculus Projects page has an example of using this data in a calculus class.

How are U.S. CO2 emissions changing?

The recent EIA report Carbon dioxide emissions from the U.S. power sector have declined 28% since 2005 (10/29/18) provides the graphic (copied here) showing the changes of the source of electricity generation and corresponding changes in CO2 emissions from 2005 to 2017.

Electricity related CO2 emissions declined but not all sectors decreased. The EIA report U.S. Energy-Related Carbon Dioxide Emissions, 2017 (9/25/18) provides a detailed analysis of U.S. CO2 emissions.  Figure 4 (copied here) from the report shows that transportation related CO2 emissions have grown, although they haven’t reached pre 2008 levels. This report contains 11 graph and 2 tables with downloadable data.

Overall U.S. CO2 emissions have declined in the last three years (see figure 1 in the second report), but unfortunately according to the IEA after little change from 2014-2016:

Global energy-related CO2 emissions grew by 1.4% in 2017, reaching a historic high of 32.5 gigatonnes, a resumption of growth after three years of global emissions remaining flat.

Further, according to the Quartz article Instead of falling, global emissions are set to rise in 2018 by Akshat Rathi (10/8/18)

“When I look at the first nine months of data, I expect in 2018 carbon emissions will increase once again. This is definitely worrying news for our climate goals,” Fatih Birol, executive director of the IEA, told the Guardian. “We need to see a steep decline in emissions. We are not seeing even flat emissions.”

Glen Peters of the Center for International Climate Research says he agrees with Birol’s assessment. Emissions from both China and the US, the world’s two largest emitters, are up in the first nine months of the year. The reason is likely tied to strong economic growth, according to Peters.


What are the recent Mauna Loa CO2 measurements?

NOAA: https://tinyurl.com/y9opmjxg

The  NOAA article Another Climate Milestone on Mauna Loa (6/7/18) provides an overview of CO2 measurement at the Mauna Loa site.  In particular,

Carbon dioxide levels measured at NOAA’s Mauna Loa Atmospheric Baseline Observatory averaged more than 410 parts per million in April and May, the highest monthly averages ever recorded, scientists from NOAA and Scripps Institution of Oceanography at the University of California San Diego announced today.

There is also this point:

From 2016 to 2017, the global COaverage increased by 2.3 ppm – the sixth consecutive year-over-year increase greater than 2 ppm. Prior to 2012, back-to-back increases of 2 ppm or greater had occurred only twice.

Why Mauna Loa?

The Mauna Loa observatory is ideally located for monitoring CO2 and other greenhouse gases in the atmosphere. Situated at more than 11,000 feet above sea level in the middle of the Pacific Ocean, the site gives researchers the opportunity to sample air that has been well-mixed during its passage across the Pacific and, thanks to its altitude, is minimally influenced by local vegetation or local pollution sources.

The article links directly to CO2 data sets and other resources.  The Calculus Projects page here has a Mauna Loa CO2 project and the Misc Materials page has the CO2 movie.

Which river basins have the most surface area covered by streams and rivers?

Also, why would we want to know this?  NASA’s Vital Signs of the Planet feature How wide are the world’s rivers?  by Adam Voiland (7/18/18) answers the questions.

Most scientists who study rivers rely on measures of discharge, the volume of water transported through a given cross-section of a river. Much less studied, though critically important, is a river’s total surface area, particularly for scientists trying to understand how carbon dioxide moves between rivers and the atmosphere.

The work has resulted in a  global database of river widths.  The map here, copied from the post, answers the main question:

The map below shows which river basins have the most surface area covered by streams and rivers. The Brahmaputra River in India and Bangladesh, the Amazon in Brazil, and the Lena in Russia are among the widest rivers—and the river networks with the largest surface areas.

Along with the river widths database the article also links to global network of stream gauges for river discharge data.


How much has growing season/allergy season increased in your town?

Climate Central has your answer with their post, Here’s How Frost-Free Season Affects Allergy Season (4/4/18). You will find a drop down menu to produce graphs like this one for Grand Rapids, which has seen as average increase of about 25 frost free days. On the downside,

 A study sampling 10 locations from Texas to Saskatoon, Canada indicated that pollen seasons lengthened between two to four weeks from 1995 to 2009, with the largest increases in the northernmost areas.

In addition, increasing atmospheric carbon dioxide enhances photosynthesis in plants, meaning that they produce more pollen.

They don’t provide the data, unfortunately, but they do provide a clear methodology so that you can create the data set for your city. You can get weather data from NOAA Climate Data Online. There is great potential here for student projects in statistics courses.

Which World Region Emits the Most CO2?

Our World in Data’s latest visualization is this graph of CO2 emissions by world region.  If you go to the page you will find the usual high quality interactive graph with data in a excel file.  You can read off the graph that in 2015 China emitted 10.23 Gt of CO2 while the U.S. emitted 5.1 Gt.  On the other hand, while China emitted about twice as much CO2 their population is about four times the size of the U.S.

Where Do Carbon Emissions Go?

Where do carbon emissions go seems like an obvious question. Into the air of course. If so, then one would expect a near perfect linear relationship between emissions and atmospheric CO2.  The graph here has yearly carbon emissions in million tonnes per year (as reported by the Global Carbon Project)  vs atmospheric CO2 in ppm from Mauna Loa (see data in the calculus project page).  The graph may not be as linear as expected and, while maybe some of it is explained by issues of mixing in the atmosphere or the need for a lag, part of the answer is based on where the carbon goes after it has been emitted.  A recent NYT article, Carbon in the Atmosphere is Rising – Even as Emissions Stabilize, sheds some light on the issue:

Scientists have spent decades measuring what was happening to all of the carbon dioxide that was produced when people burned coal, oil and natural gas. They established that less than half of the gas was remaining in the atmosphere and warming the planet. The rest was being absorbed by the ocean and the land surface, in roughly equal amounts.

In essence, these natural sponges were doing humanity a huge service by disposing of much of its gaseous waste. But as emissions have risen higher and higher, it has been unclear how much longer the natural sponges will be able to keep up.

In fact, much of the carbon is absorbed in the ocean and land surface, and that will add variability to the relationship. The Global Carbon Project has this data available and it can be used by teachers. Go to their page and click on the global budget link for the data, which includes ocean and land sinks of carbon.  If you want the data that created the graph on this page go here.