Home / Tag Archives: climate change

Tag Archives: climate change

How warm was 2018?

A number of agencies have reported that 2018 was the fourth hottest year on record. The report from NASA GIS, 2018 Fourth Warmest Year in Continued Warming Trend, According to NASA, NOAA (2/6/19) includes a short video showing the warming of the planet while including other facts. The report also includes the animated graph, copied here, with temperature trends from five different agencies.

Global temperatures in 2018 were 1.5 degrees Fahrenheit (0.83 degrees Celsius) warmer than the 1951 to 1980 mean, according to scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York. Globally, 2018’s temperatures rank behind those of 2016, 2017 and 2015. The past five years are, collectively, the warmest years in the modern record.

The post includes a link to data.

How quickly is Antarctica losing ice?

Time series of cumulative anomalies in SMB (blue), ice discharge (D, red), and total mass (M, purple) with error bars in billions of tons for (A) West Antarctica, (B) East Antarctica; (C) Antarctic Peninsula), and (D) Antarctica, with mean mass loss in billions of tons per year and an acceleration in billions of tons per year per decade for the time period 1979 to 2017.

 

The new paper, Four decades of Antarctic Ice Sheet mass balance from 1979–2017, by Eric Rignot, et. el (PNAS 1/14/19) states

The total mass loss from Antarctica increased from 40 ± 9 Gt/y in the 11-y time period 1979–1990 to 50 ± 14 Gt/y in 1989–2000, 166 ± 18 Gt/y in 1999–2009, and 252 ± 26 Gt/y in 2009–2017, that is, by a factor 6.

An interesting fact from the paper:

Antarctica contains an ice volume that translates into a sea-level equivalent (SLE) of 57.2 m.

Note: 52.2m is about 188 feet. The graph with caption here is from the paper. The Washington Post has a summary of the paper in the article Ice loss from Antarctica has sextupled since the 1970s, new research finds by Chris Mooney and Brady Dennis (1/14/19) and notes

It takes about 360 billion tons of ice to produce one millimeter of global sea-level rise.

Based on the last two quotes, How much ice is there on Antarctica?  NASA’s Vital Signs of the Planet has Antarctica Ice data on their Ice sheets page.

Related Post: How well do we understand rising sea levels?

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.

Follow Up: How old is Arctic Ice?

In a follow up to our May 28, 2018 post, How old is Arctic Ice?, the Washington Post has an article, The Arctic Ocean has lost 95 percent of its oldest ice — a startling sign of what’s to come by  Chris Mooney (12/11/18). It notes:

In 1985, the new NOAA report found, 16 percent of the Arctic was covered by the very oldest ice, more than four years old, at the height of winter. But by March, that number had dropped to under 1 percent. That’s a 95 percent decline.

At the same time, the youngest, first-year ice has gone from 55 percent of the pack in the 1980s to 77 percent, the report finds. (The remainder is ice that is two to three years old.)

The loss of sea ice creates a feedback loop:

There is a well-known feedback loop in the Arctic, caused by the reflectivity of ice and the darkness of the ocean. When the Arctic Ocean is covered by lighter, white ice, it reflects more sunlight back to space. But when there is less ice, more heat gets absorbed by the darker ocean — warming the planet further. That warmer ocean then inhibits the growth of future ice, which is why the process feeds upon itself.

and

Because of this, Arctic sea ice loss has already increased the warming of the planet as a whole. Ramanathan said the impact is equivalent to the warming effect of 250 billion tons of carbon dioxide emissions, or about six years of global emissions.

Ramanathan fears that entirely ice-free summers, if they began to occur regularly, could add another half- degree Celsius (0.9 degrees Fahrenheit) of warming on top of whatever else the planet has experienced by that time.

The Washington Post article has a few nice animated graphics. The graph and map here is from the sea ice sections of the Arctic Report Card: Update for 2018 – Effects of persistent Arctic warming continue to mount from NOAA. The Arctic Report card contains a half dozen charts and graphs including one that compares March and September sea ice extent. A data and project for this is in our Statistics Project page.

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 fast is runoff from Greenland ice sheet increasing?

The Nature article Nonlinear rise in Greenland runoff in response to post-industrial Arctic warming by Luke Trusel et. el. (12/5/18)  reports on Greenland ice sheet runoff.  Referring to fig 4a (copied here) in their paper

We show that an exceptional rise in runoff has occurred over the last two decades, equating to an approximately 50% increase in GrIS-integrated runoff compared to pre-industrial runoff, and a 33% increase over the twentieth century alone.

The Woods Hole Oceanographic Institution (WHOI) provides a less technical summary of the paper in their post Greenland Ice Sheet Melt ‘Off the Charts’ Compared With Past Four Centuries (12/5/18).

Ice loss from Greenland is one of the key drivers of global sea level rise. Icebergs calving into the ocean from the edge of glaciers represent one component of water re-entering the ocean and raising sea levels. But more than half of the ice-sheet water entering the ocean comes from runoff from melted snow and glacial ice atop the ice sheet. The study suggests that if Greenland ice sheet melting continues at “unprecedented rates”—which the researchers attribute to warmer summers—it could accelerate the already fast pace of sea level rise.

“Rather than increasing steadily as climate warms, Greenland will melt increasingly more and more for every degree of warming. The melting and sea level rise we’ve observed already will be dwarfed by what may be expected in the future as climate continues to warm,” said Trusel.

The WHOI post includes a short video with a graph similar to the one copied here and a summary of the science.  The Nature article has data available.

As an aside, while we are talking about Greenland,  in NASA news International team – NASA make unexpected discovery under Greenland ice (11/15/18)

An international team of researchers, including a NASA glaciologist, has discovered a large meteorite impact crater hiding beneath more than a half-mile of ice in northwest Greenland. The crater — the first of any size found under the Greenland ice sheet — is one of the 25 largest impact craters on Earth, measuring roughly 1,000 feet deep and more than 19 miles in diameter, an area slightly larger than that inside Washington’s Capital Beltway.

The NASA article includes a short video.

What are six trends in western U.S. wildfires?

NASA’s Earth Right Now blog post  Six trends to know about fire season in the western U.S. by Kasha Patel (12/5/18) provides these trends.  The first (see graph copied here from NASA RECOVER/Keith Weber),

Over the past six decades, there has been a steady increase in the number of fires in the western U.S. In fact, the majority of western fires—61 percent—have occurred since 2000.

There are five other trends with another graph and three maps. The last one notes

Research suggests that global warming is predicted to increase the number of very large fires (more than 50,000 acres) in the western United States by the middle of the century (2041-2070).

The map below shows the projected increase in the number of “very large fire weeks”—periods where conditions will be conducive to very large fires—by mid-century (2041-2070) compared to the recent past (1971-2000). The projections are based on scenarios where carbon dioxide emissions continue to increase.

There isn’t a direct link to the data for the graph here or the other one, but the link to the slides of Keith Weber include an email address. Requests for data for educational purposes are often successful.

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.

 

How do we take the temperature of the oceans?

APO is atmospheric potential oxygen.

The recent BBC article Climate change: Oceans ‘soaking up more heat than estimated’  b

The key element is the fact that as waters get warmer they release more carbon dioxide and oxygen into the air.

“When the ocean warms, the amount of these gases that the ocean is able to hold goes down,” said Dr Resplandy.

“So what we measured was the amount lost by the oceans, and then we can calculate how much warming we need to explain that change in gases.”

The image here is copied from the original article in Nature, Quantification of ocean heat uptake from changes in atmospheric O2 and COcomposition by Resplandy et. el (10/31/18) . The abstract to the paper provides a nice summary:

The ocean is the main source of thermal inertia in the climate system1. During recent decades, ocean heat uptake has been quantified by using hydrographic temperature measurements and data from the Argo float program, which expanded its coverage after 20072,3. However, these estimates all use the same imperfect ocean dataset and share additional uncertainties resulting from sparse coverage, especially before 20074,5. Here we provide an independent estimate by using measurements of atmospheric oxygen (O2) and carbon dioxide (CO2)—levels of which increase as the ocean warms and releases gases—as a whole-ocean thermometer. We show that the ocean gained 1.33 ± 0.20  × 1022 joules of heat per year between 1991 and 2016, equivalent to a planetary energy imbalance of 0.83 ± 0.11 watts per square metre of Earth’s surface. We also find that the ocean-warming effect that led to the outgassing of O2 and CO2 can be isolated from the direct effects of anthropogenic emissions and CO2 sinks. Our result—which relies on high-precision O2 measurements dating back to 19916—suggests that ocean warming is at the high end of previous estimates, with implications for policy-relevant measurements of the Earth response to climate change, such as climate sensitivity to greenhouse gases7 and the thermal component of sea-level rise8.

The paper has other interesting graphs that could be used in a QL based class. For a calculus class, the graph here is an example of the use of the Δx notation in the “real world”.

How are climatic zones changing?

The Yale Environment 360 article Redrawing the Map: How the World’s Climate Zones Are Shifting  by Nicola Jones (10/23/18)  provides animated maps, such as the one below, and quantitative statements about changing ecology including rates (great for a calculus class):

Lauren Parker and John Abatzoglou of the University of Idaho tracked what would happen to hardiness zones from 2041 to 2070 under future global warming scenarios, and found the lines will continue to march northward at a “climate velocity” of 13.3 miles per decade.

One study in northern Canada found that the permafrost around James Bay had retreated 80 miles north over 50 years. Studies of ground temperatures in boreholes have also revealed frightening rates of change, says Schafer. “What we’re seeing is 20 meters down, it’s increasing as high as 1-2 degrees C per decade,” he says. “In the permafrost world that’s a really rapid change. Extremely rapid.”

North America is seeing the opposite phenomenon: Its arable land is romping northward, expanding the wheat belt into higher and higher latitudes. Scientists project it could go from about 55 degrees north today to as much as 65 degrees North — the latitude of Fairbanks, Alaska — by 2050. That’s about 160 miles per decade.

The article includes potential ramifications of these changes along with other quantitative information.

Graphic: Hardiness zones in the U.S., which track average low temperatures in winter, have all shifted northward by half a zone warmer since 1990. SOURCE: UNITED STATES DEPARTMENT OF AGRICULTURE. GRAPHIC BY KATIE PEEK.