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Tag Archives: climate change

What is in the new IPCC report?

The is too much in the new IPCC report (released this week) to cover here, but we can highlight a couple of points. The first is their graph copied here.  The main graph provides projections for change in global temperature based on what happens to CO2 and non-CO2 radiative forcing gasses.  For example, if net CO2 emissions reach zero by 2055 (CO2 emitted minus CO2 absorbed graph b) and non-CO2 gases are reduces (graph d), then we are likely to stay below the 1.5 °C threshold.  What the graph does not say is what happens if society does nothing.

We recently posted about see level and here is an excerpt from the report about that:

Model-based projections of global mean sea level rise (relative to 1986-2005) suggest an indicative range of 0.26 to 0.77 m by 2100 for 1.5°C global warming, 0.1 m (0.04-0.16 m) less than for a global warming of 2°C (medium confidence). A reduction of 0.1 m in global sea level rise implies that up to 10 million fewer people would be exposed to related risks, based on population in the year 2010 and assuming no adaptation (medium confidence). {3.4.4, 3.4.5, 4.3.2}

The executive summary and/or the graphs could be used in QL rich courses.

How well do we understand rising sea levels?

An ice-choked fjord in Greenland. Image credit: NASA/JPL-Caltech.

NASA’s Vital Signs of the Planet feature,  Keeping score on Earth’s rising seas by Pat Brennan (9/1918) summarizes a recent paper that  “ ‘closes’ the sea-level budget to within 0.3 millimeters of sea-level rise per year since 1993.”

A just-published paper assembles virtually all the puzzle pieces – melting ice, warming and expanding waters, sinking coastlines and a stew of other factors – to arrive at a picture of remarkable precision. Since 1993, global sea level has been rising by an average 3.1 millimeters per year, with the rise accelerating by 0.1 millimeter per year, according to the study published Aug. 28 in the journal, “Earth System Science Data.”

“Global mean sea level is not rising linearly, as has been thought before,” said lead author Anny Cazenave of France’s Laboratory for Studies in Geophysics and Oceanography (LEGOS). “We now know it is clearly accelerating.”

The above paragraphs can be used as calculus in the news and sea level data is available from NASA’s Sea Level page.

How much have fall temperatures risen?

According to the Climate Central post, Fall Warming Trends Across the U.S. (9/5/18), the average fall temperature for the U.S. has risen nearly 3°F since 1970 (see their graph copied here).  Why does this matter:

Insects linger longer into the fall when the first freeze of the season comes later in the year. A new study from the Universities of Washington and Colorado indicates that for every degree (Celsius) of warming, global yields of corn, rice, and wheat would decline 10 to 25 percent from the increase in insects. Those losses are expected to be worst in North America and Europe.

The article has a drop down menu to select cities across the U.S. to see a graph similar to the one copied here for the selected city.  They don’t post the data that was used to create the graphs but they do explain their data sources under methodology.

A statistics project could have students create this graph for their hometown.  One way to obtain the data was noted in our post, What do we know about nighttime minimum temperatures?: Go to  NOAA’s Local Climatological Data Map. Click on the wrench under Layers. Use the rectangle tool to select your local weather station. Check off the station and Add to Cart. Follow the direction from their being sure to select csv file. You will get an email link for the data within a day.  Note: You are limited in the size of the data to ten year periods. You will need to do this more than once to get the full data set available for your station.



How does climate change impact the spin axis of the planet?

Source: NASA

NASA’s Vital Signs of the planet post, Scientists ID three causes of Earth’s spin axis drift (9/19/18) explains changes in the spin axis.

Earth is not a perfect sphere. When it rotates on its spin axis — an imaginary line that passes through the North and South Poles — it drifts and wobbles. These spin-axis movements are scientifically referred to as “polar motion.” Measurements for the 20th century show that the spin axis drifted about 4 inches (10 centimeters) per year. Over the course of a century, that becomes more than 11 yards (10 meters).

In general, the redistribution of mass on and within Earth — like changes to land, ice sheets, oceans and mantle flow — affects the planet’s rotation. As temperatures increased throughout the 20th century, Greenland’s ice mass decreased. In fact, a total of about 7,500 gigatons — the weight of more than 20 million Empire State Buildings — of Greenland’s ice melted into the ocean during this time period. This makes Greenland one of the top contributors of mass being transferred to the oceans, causing sea level to rise and, consequently, a drift in Earth’s spin axis.

The article explains why the Greenland Ice sheet has such an impact. NASA has also produced an interactive simulation on how different processes contribute to the wobble. There could be a nice vector calculus, linear algebra, or geometry exercises here.

How are blocking high, climate change, & hurricane Florence related?

Credit: Weather.com via Think Progress

The Think Progress article, Global warming ‘double whammy’ may be steering Florence into the Carolinas, says researcher by Joe Romm (9/12/2018) makes the connection.

The path of Florence has been extremely unusual. As Philip Klotzbach, an Atlantic hurricane expert, tweeted on Friday, “33 named storms (since 1851) have been within 100 miles of Florence’s current position. None of these storms made US landfall. The closest approach was Hurricane George (1950) — the highlighted track [in white].”

Florence, tragically, has made a beeline toward the Carolinas. And it clearly was steered away from the historical (or “climatological”) path by a major high-pressure system blocking its typical path — north and away from land.

Back in 2016 Francis published a study on the link between blocking highs and global warming. At the time, she told ThinkProgress: “Our new study does indeed add to the growing pile of evidence that amplified Arctic warming and sea-ice loss favor the formation of blocking high pressure features in the North Atlantic. These blocks can cause all sorts of trouble…”

There are more details in the well cited article. Sustainabilitymath posted about hurricanes last year, Are We Seeing More Hurricanes in the North Atlantic?, which inlcudes a link to hurricane data.

How many 90+ degree days will your hometown have in the future?

The New York Times interactive article How Much Hotter Is Your Hometown Than When You Were Born? By Nadja Popovich, Blacki Migliozzi, Rumsey Taylor, Josh Williams and Derek Watkins, allows the reader to input a birth year and hometown and provides a graph with historical 90+ degree days and predictions for the future. For example a person born in 1970 in NYC would get the graph copied here.  In 1970 the expectation was six 90+ degree days, today it is 11, and by 2050 it will be 24 with a likely range of 15 to 30.

THE NEW YORK AREA is likely to feel this extra heat even if countries take action to lower their emissions by the end of the century, according to an analysis conducted for The New York Times by the Climate Impact Lab, a group of climate scientists, economists and data analysts from the Rhodium Group, the University of Chicago, Rutgers University and the University of California, Berkeley. If countries continue emitting at historically high rates, the future could look even hotter.

The future projection shown here assumes countries will curb greenhouse gas emissions roughly in line with the world’s original Paris Agreement pledges (although most countries do not appear on track to meet those pledges).

There are related human health impacts:

Worldwide, high temperatures have been found to increase the risk of illness and death, especially among older people, infants and people with chronic medical conditions. Lower-income populations, which more often lack access to air conditioning and other adaptive technologies, are also more likely to suffer the impacts of extreme heat. In America, so are people of color.

The article has other graphs and quantitative information which can be used in  QL based course.

How has Arctic sea ice volume changed?

The Guardian article Arctic’s strongest sea ice breaks up for first time on record by Jonathan Watts (8/21/18) includes an animated graph of Arctic sea ice volume by year. We produce a similar graph using monthly average ice volume from PIOMAS (source cited for the data in the article).  The graph clearly displays the change of ice throughout the year and the loss of ice throughout the years.

Freakish Arctic temperatures have alarmed climate scientists since the beginning of the year. During the sunless winter, a heatwave raised concerns that the polar vortex may be eroding.

This includes the Gulf Stream, which is at its weakest level in 1,600 years due to melting Greenland ice and ocean warming. With lower circulation of water and air, weather systems tend to linger longer.

A dormant hot front has been blamed for record temperatures in Lapland and forest fires in Siberia, much of Scandinavia and elsewhere in the Arctic circle.

The data from PIOMA includes monthly and daily ice volumes.  The R script and csv file that produced the graph here can be downloaded.

How much has the High Plains (or Ogallala) aquifer declined?

Source: USGS

The USGS post High Plains Aquifer Groundwater Levels Continue to Decline (6/16/17) summarizes the results from the USGS report Water-Level and Recoverable Water in Storage Changes, High Plains Aquifer, Predevelopment to 2015 and 2013–15.

In 2015, total recoverable water in storage in the aquifer was about 2.91 billion acre-feet, which is an overall decline of about 273.2 million acre-feet, or 9 percent, since predevelopment. Average area-weighted water-level change in the aquifer was a decline of 15.8 feet from predevelopment to 2015 and a decline of 0.6 feet from 2013 to 2015.

A little geography:

The High Plains aquifer, also known as the Ogallala aquifer, underlies about 112 million acres, or 175,000 square miles, in parts of eight states, including: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas and Wyoming. The USGS, at the request of the U.S. Congress and in cooperation with numerous state, local, and federal entities, has published reports on water-level changes in the High Plains aquifer since 1988 in response to substantial water-level declines in large areas of the aquifer.

A more recent article in the Conversation, Farmers are drawing groundwater from the giant Ogallala Aquifer faster than nature replaces it by Char Miller (8/7/18) provides context around the loss of water in the Ogallala. 

In my view, Plains farmers cannot afford to continue pushing land and water resources beyond their limits – especially in light of climate change’s cumulative impact on the Central Plains. For example, a recent study posits that as droughts bake the land, lack of moisture in the soil actually spikes temperatures. And as the air heats up, it further desiccates the soil.

This vicious cycle will accelerate the rate of depletion. And once the Ogallala is emptied, it could take 6,000 years to recharge naturally. In the words of Brent Rogers, a director of Kansas Groundwater Management District 4, there are “too many straws in too small of a cup.”

The USGS post and the Conversation article are useful for a QL based course. The full USGS report has links to water-level data sources starting on page 7.

What do we know about nighttime minimum temperatures?

The recent article on Climate.gov Extreme overnight heat in California and the Great Basin in July 2018 by Rebecca Lindsey (8/8/18) provides an overview in context.

As the NCEI’s Deke Arndt has blogged about before, nighttime low temperatures are increasing faster than daytime high temperatures across most of the contiguous United States. For much of the West and Southwest, July’s record-breaking nighttime heat is a new highpoint in a long-term trend—one that has rapidly accelerated in recent decades. In California, average overnight low temperature in July rose by 0.3°F per decade over the historical record (1895-2018), but since 2000, the pace of warming has accelerated to 1.3°F per decade.

Here is an example of why this matters:

According to Tim Brown, director of NOAA’s Western Region Climate Center (WRCC), it’s a pattern that has serious consequences for wildfires and those who combat them. When temperatures cool off overnight, it’s not just a physical relief for firefighters who may be working in conditions that push the limits of human endurance; fire behavior itself relaxes as temperatures drop, winds grow calmer, and relative humidity rises.

The graph here for California July minimum temperature is from the article. A stats course can have students create a similar graph for their hometown. Go to  NOAA’s Local Climatological Data Map. Click on the wrench under Layers. Use the rectangle tool to select your local weather station. Check off the station and Add to Cart. Follow the direction from their being sure to select csv file. You will get an email link for the data within a day.  Note: You are limited in the size of the data to ten year periods. You will need to do this more than once to get the full data set available for your station.

The map here  shows statewide minimum temperature ranks for July 2018.  It is from NOAA’s National Temperature and Precipitation Maps page.  Under products select Statewide Minimum Temperature Ranks and choose the desired time period.  A map similar to the one in the article can be generated by selecting CONUS Gridded Minimum Temperature Ranks.

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.