Earlier this year (“Whose Amazon” September 2, 2019), I wrote about the fires in the Amazon at the time when the French and Brazilian heads of state were exchanging personal insults. G7 leaders attacked the Brazilian president for torching the “lungs of the planet,” and Brazil’s President Bolsonaro told the Europeans to mind their own business, indicating Brazilian natural resources were Brazil’s to exploit, despite protestations from overseas “colonialists.” In a speech to the United Nations, he rejected notions that the “Amazon is a world heritage” (Washington Post, September 24, 2019).
He has repeatedly asserted that indigenous reserves should “no longer be demarcated” and contain valuable mineral, timber and agricultural resources which need to be developed. (https://www.socioambiental.org/en/noticias-socioambientais/what-changes-or-is-left-for-indigenous-people-with-president-bolsonaros-reforms-in-brazil). These reserves represent both human and ecological havens; they are home to the remaining 850,000 indigenous peoples of Brazil and contain largely undisturbed and intact forest ecosystems. They also contain nearly 13% of Brazil’s total land area, occupied by handfuls of indigenous peoples (<1% of Brazil’s population), with weak governance and policing—almost overwhelmingly attractive targets for development.
When I wrote the earlier blog, fire activity in Brazil as a whole and the Amazon was not remarkably elevated over previous years, relative to the historical record dating to 2001. This assessment is still true through the year to date, but with some important revisions.
Fire activity within the Amazonas region appears to be nearly as high as 2015, making 2019 the third highest fire season from 2001 onwards. The combined MODIS and VIIRS data (starting in 2012) posted on the globalfiredata.org website through October 7, 2019, show that fire detections are not as high as those detected in 2012, nor as high as 2017 (see the Modis alert figure above).
Absent aggressive pressure from countries that import Brazilian beef and soy (two of the commodities linked to deforestation and land conversion), coupled with widespread opposition to continued development within Brazil, land transformation across many regions of Brazil, particularly the remaining, largely intact areas located in demarcated indigenous reserves, will continue and accelerate. It is very likely the fundamental character of much of Brazil’s vast undeveloped regions will be decided during the course of the next decade.
One would think the latest reports documenting the lack of action regarding climate change, the continued and accelerating changes to the oceans and cryosphere, the deteriorating condition of the Great Barrier Reef, and the astonishing decline in avian populations along with the ongoing extinction of numerous other plant and animal species, should serve to focus global attention on planetary change in the Anthropocene. Unfortunately, it would appear that business as usual will be the most likely outcome of all these reports, despite much wringing of hands, gloomy predictions and opining of pundits, experts and the like.
A hallmark of the Anthropocene is the observably (much!) higher rate of change in many Earth system processes as compared to “background” rates determined from historical records. This acceleration has been well documented, but very poorly communicated to the general public and largely ignored by decision makers. Rising concentrations of carbon dioxide, increasing sea and land temperatures, accelerated melt rates of sea ice, permafrost and ice sheets, along with rising sea level, inform us that a critical fork in the road lies ahead. Ignore these signposts and there will be no opportunity to even make a choice as to which road we take—the decision will have been already made.
With this analogy in mind, I turn to three papers, one written in 1976, one in 2013, and another released this September. In 2013, James Hansen and 17 other scientists published “Assessing ‘Dangerous Climate Change’: Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature.”( Dangerous climate change) Their paper documented the continued rise in atmospheric carbon dioxide from fossil fuel combustion, along with the various attendant impacts to Earth system processes, the environment and human health and well-being arising from this accumulation. The authors suggested that the inertia of the climate system causes it to respond “slowly to this man-made forcing,” complicating policy responses, as well as obscuring the potentiality for irreversible climate change due to slow feedbacks. Although the rapidity and scale of such changes; e.g., irreversible melting of Antarctic and/or Greenland ice sheets remains unclear, continued combustion of fossil fuels threatens to lock us into this future.
They argued that the implications of future climate change already “in the pipeline” are thus intergenerational, presenting young people of today with a future they will have had no hand in shaping. The authors suggested that “(a) scenario is conceivable in which growing evidence of climate change and recognition of implications for young people lead to massive public support for action” based on the expectation of “fairness and justice in a matter as essential as the condition of the planet they will inhabit.” This sounds remarkably like the argument underlying today’s campaign by young people for climate justice. The conclusions of the 2013 paper are stark: the opportunity to avoid climate disruptions and maintain global temperatures below 2oC will require “extraordinarily rapid emission reductions” and choosing an alternative energy pathway, a “fork in the road” from a carbon-rich energy path to one that is carbon-free.
The choice of a “hard energy path” as opposed to a “soft energy path” was outlined more than forty years ago, in Amory Lovin’s seminal October 1976 Foreign Affairs article “Energy Strategy: The Road Not Taken?” (Soft Energy Paths) in which he outlined the numerous benefits of shifting from a “hard path” of fossil fuels and nuclear power to a “soft path” of efficiency and renewable energy, focused on matching the quality of energy to its end use. Lovins’ deeply controversial and influential article showed a way forward to an energy future that today bears a remarkable similarity to his original description. However, despite rapid efficiency improvements, technological breakthroughs and movement along a soft energy path envisioned by Lovins, a key aspect of the soft energy path, deployment of renewables, lags approximately 25 years behind the 1976 projections. Deployment of renewables must therefore accelerate even more rapidly if we are to move towards an energy future that will avoid the irreversible climate change outlined by Hansen et al.
These choices are now before us, laid out in a September 2019 White Paper from the World Economic Forum, “The Speed of the Energy Transition—Gradual or Rapid Change?” (The speed of the energy transition) The paper poses the question “Will the global energy transition from fossil fuels to sustainable energy be gradual or rapid?” The authors suggest the choice of paths will be made this decade, that the two paths are mutually exclusive, and that the choice of business as usual “regrettably … means that the goals of the Paris Agreement will become increasingly unachievable.”
There are three “signposts” along the path to a Rapid global
energy transition by 2030 according to the White Paper:
(1) solar electricity
at $20-$30 per megawatt hour
(2) carbon taxes
implemented on around half of emissions at $20 per tonne
(3) three peaks to
take place in the 2020’s
a. peak demand for new internal combustion
b. peak demand for fossil fuels in electricity
c. peak demand for all fossil fuels
If we pass these, the Rapid transition is on track; failure to pass these leads to a future whose socioeconomic and Earth system dimensions will be dictated by processes humanity has set into irreversible motion. The chart from Hansen, et al hints at the potential long lags in the climate system’s response to fossil fuel emission cuts: it could take centuries before atmospheric carbon dioxide levels return to “safe” levels of 350 ppm.
The chart below from BerkelyEarth shows the path to 1.5oC is only a decade or so distant, if current trends continue. The chart shows a ten-year moving average of the Earth’s surface temperature, plotted relative to the average temperature from 1850-1900. At the current rate of increase, 1.5oC above the 1850-1900 average will be reached by 2035.
According to Hansen et al., warming will reach 1.5oC and “stay above 1.0oC until 2400 if emissions continue to increase until 2030.”
Perhaps Greta Thunberg said it best in her September 23
address to the United Nations:
“For more than 30 years, the science has been crystal clear. How dare you continue to look away and come here saying that you’re doing enough, when the politics and solutions needed are still nowhere in sight…The popular idea of cutting our emissions in half in 10 years only gives us a 50% chance of staying below 1.5 degrees [Celsius], and the risk of setting off irreversible chain reactions beyond human control…Fifty percent may be acceptable to you. But those numbers do not include tipping points, most feedback loops, additional warming hidden by toxic air pollution or the aspects of equity and climate justice…You are failing us. But the young people are starting to understand your betrayal. The eyes of all future generations are upon you. And if you choose to fail us, I say: We will never forgive you.
We will not let you get away with this. Right here, right now is where we draw the line. The world is waking up. And change is coming, whether you like it or not.” (Thunberg Transcript)
“Our house is on fire,” declared French President Macron,
describing the fires burning across Brazil’s vast interior. Satellite imagery revealed clouds of smoke
from the thousands of fires obscuring large portions of South America,
including the skies of Sao Paulo on Monday, August 20. News outlets described the Amazon forests as
the “lungs of the planet,” and articles warned of the Amazon “tipping” from its
present forested state to one in which only savannah ecosystems could
survive. Blame for the fires was laid at
the feet of President Bolsonaro, whose anti-environmental, pro-development
policies were encouraging rampant conversion of forests to agriculture, mining,
timber, and cattle operations.
President Bolsonaro’s position on the use of Brazil’s natural resources has been clear: Brazil, not the international community will determine their best use. Concern regarding the ongoing Amazon fires was highlighted at the just-concluded G7 meeting in Biarritz, where President Macron had declared them a “global emergency,” and the G7 agreed to provide funding to fight the fires and aid in reforestation. (The Guardian, August 26, 2019) However, in a tweet, President Bolsonaro appeared to reject the G7 proposal, asserting that the G7 was treating Brazil as a colonial entity. A further exchange of tweets between the French and Brazilian leaders ensued, which did little to ease the situation.
Is This Fire Season Different?
The fire season in the southern Amazon runs from June to December, with peak burning activity in September (Global Fire Data) This website has a great deal of information regarding global fire activity, so let’s take a look at some of the data for the Amazon Region (“Legal Amazon”). Since 2012, VIIRS satellite data has been available along with the older, somewhat less accurate MODIS data. (The VIIRS data has a resolution of about 375 meters, as compared to about 1 kilometer for MODIS.)
Here are a few highlights:
1. As of August 31, the 2019 fire season has the highest count since 2012, when VIIRS data became available.
2. Fires in 2019 are more
intense than in previous years, as measured in terms of radiative power.
3. There has been a noticeable increase in large, intense, and persistent fires burning along major roads in the central Brazilian Amazon, which is more consistent with land clearing than regional drought. (NASA Earth Observatory) As an example, the screenshot below is an enlargement of an unprotected area in Para’ shows the clustering of fires adjacent to existing roads in the middle of the image. Darker areas are unprotected forests, lighter areas above and below the dark green are National Parks.
4. However, if we look at 2019 MODIS Fire Alerts, through August 31 for all of Brazil, 2019 (red line) doesn’t look at all unusual as compared to many other fires seasons.
5. Another representation of the historical data reinforces this impression that the 2019 fire season may be well below many other years.
6. Fire alerts in Intact Forest Landscape Areas appear to include only 6% of the impacted areas.
It’s Too Early To Draw Conclusions
There is no doubt that August 2019 has seen an historically high number of fires in the Amazon, but we will not have the full picture until the end of the fire season, when satellite imagery can be compared to pre-2019 data to determine the precise location and true extent of the fires. The degree to which previously intact tropical forest or other threatened biomes have been transformed by fire won’t be known until this type of analysis can be made. Satellite imagery clearly shows many fires both within and adjacent to Brazilian National Parks. For example, the screenshot below (NASA Fire Information for Resource Management System (FIRMS)) shows an area of Para’ with numerous fires in the dark greenish black (unprotected) areas as well as in the protected (lighter green) areas.
However, cumulative monthly fire counts (January-August 31) for 2019 in Para’ are well below many other years (next figure), a further indication that it is simply too soon to draw conclusions and issue condemnations about the overall extent of fire damage.
Global Demand Drives Local Change
To return to President Bolsonaro’s assertion that the disposition of Brazil’s forest resources are a Brazilian, not international issue, this is a much more complicated issue than the President’s statement would indicate. Surging global demand for soy has been met by Brazil, Argentina and the United States. As of 2018, it is likely that Brazil will surpass the United States as both the largest producer and exporter of soy.(TRASE Yearbook 2018) Brazil has produced soy first by converting vast undeveloped subtropical regions in its south, then into tropical areas, into the Cerrado (largest savanna region in South America, largely unprotected) in the mid-1990’s, and now into the agricultural frontier area of Matopiba. The conversion of undisturbed forests and other biomes in Brazil to the production of soy as well as other agricultural products (e.g., sugarcane, beef, timber) has been well-documented and ongoing for many years. Soybean exports are now valued at over USD 20 billion, making them Brazil’s most valuable export commodity. (TRASE Yearbook 2018)
An estimated 1.8 million ha of soy in the Amazon in 2016 and 3.5 million ha of soy in the Cerrado in 2015 were undeveloped in the year 2000—amounting to about 40% and 20% of the total area of soy in each biome (TRASE Yearbook 2018 Chapter 3)
A complex network of producers, export and import entities links local land use change across Brazil to global consumers. The screenshots from the website (TRASE) illustrates some of these linkages. Soy is used as feed for pigs and chickens, and is exported in vast quantities to China, the world’s largest producer and consumer of pork. (Brazil is also the world’s largest exporter of chickens.) The pig population in China is estimated to be nearly 500,000,000 and China doesn’t have the land to supply soy for this plethora of pork. Instead, it has reduced the amount of land planted to soy and become the world’s largest consumer of soy (around 60% of global exports), primarily from Brazil.
This dependence on Brazilian soy will likely increase due to the ongoing and escalating trade war between the United States and China. Prior to the imposition of tariffs, Chinese soy demand had also been met by the United States, but the tariff war is likely to incentive the Brazilians to increase soy production, as China shifts from America to Brazil to meet its soy needs. In a grim analysis of the possible deforestation consequences of such a shift, a report in Nature (Trade War Disaster for the Amazon) in March estimated that “soya-bean production in Brazil could increase by up to 39%, to 13 million hectares.” Following the historical pattern of Brazilian soy production, the ready availability undeveloped land will lead to agricultural extensification, rather than intensification.
U.S. Farmers Expand Production
Just as their Brazilian counterparts, American farmers respond to global and domestic demands agricultural commodities by expanding production. They have planted more soy for export, and they have planted more corn in response to biofuel mandates by the federal government. This has come largely at the expense of previously intact grasslands.* In the 8 year period between 2008 and 2016, 10 million acres (4,047,000 ha) of grassland, shrubland, wetland and forestland were converted to crop production in the United States, more than half of which was planted in corn and soy. 80% of new cropland came from grassland ecosystems, of which 2.2 million acres were intact grasslands, defined as “those which had not been previously planted or plowed and are most likely to contain native species and sod.” The rate of land conversion has continued at nearly 1 million acres per year.
The conversion of grassland between 2008-2012 released
more than 14 million metric tons of carbon per year—equivalent to yearly
emissions from 13 coal-fired power plants.
This extensification of agricultural production has occurred in the Dakotas, Iowa, Missouri, Kansas, Oklahoma, and Texas, Kentucky and Tennessee, as well as areas bordering Canada in the Northern Great Plains. As in the case of Brazil, extensification has converted previously intact ecosystems, which provide valuable environmental services, including protection of water quality, critical habitat for bird species, pollination, prevention of soil and nutrient loss, and carbon sequestration. In the case of grassland ecosystems as well as tropical forests, carbon sequestration is particularly important as a means of buffering continued accumulation of anthropogenically sourced carbon dioxide in the atmosphere.
Conversion of intact biomes to agroecosystems is not unique
to Brazil or the United States; agriculture occupies about 38% of Earth’s
terrestrial surface, making it the largest use of land on the planet (Solutions for A Cultivated
Planet). Flows of energy, resources,
information, etc., couple human socioeconomic systems and environmental
systems, forming a telecoupled system (Framing
Sustainability in a Telecoupled World, one of the hallmarks of the
Anthropocene. The relationship between China and Brazil exemplifies this
system, driving both extensification and intensification of soy production in
Brazil, as vast quantities of soy product flow back to China. Smaller quantities flow to many other
nations, including members of the G7. Through the work of TRASE researchers, the linkages between
import/export entities and deforestation have been brought into the open, and
it has become clear that a handful of enormous, largely privately held
companies dominate these flows. Land use
decisions in Brazil are thus determined by both Brazilian governmental
decisions, as well as those of these often vertically integrated transnational
In a telecoupled world, it is increasingly difficult to
disentangle local land use decisions from global economic forces. Thus, President Bolsinaro’s claim that
Brazilian resources are to be disposed of only by Brazil, is not really that
simple. Brazilian resource decisions can be influenced by end-users, mediated
by a very complex interplay of actors. Ultimately making a transition to
sustainability in the Amazon and elsewhere will be very challenging. For example, despite the much larger volume
of soy exports from Brazil to China, the sourcing of soy from Brazil to Europe
actually exposes European nations to higher deforestation risk than China (TRASE 2018 Annual Report)
We Are All Complicit
In a telecoupled world of nearly 8 billion, conversion of
vast ecosystems matters in ways that weren’t apparent in earlier eras. In the plow up of the Great Plains grassland
of the United States in the 19th and early 20th century,
the near extinction of the buffalo, decimation and relocation of indigenous
peoples wasn’t an issue of global concern.
Now, when Brazil is treating its vast frontier regions in much the same
fashion as did the United States, it does matter.
We in the developed world still have our hands dirty; be it
grassland conversion in the United States, deforestation of boreal forests in
Canada, destruction of the ancient Hambach Forest in Germany for production of
lignite—one of the dirtiest of coals.
Why should the Brazilians listen to us?
Moreover, why should the Brazilians change their behavior? Perhaps the Chinese should reduce their pork consumption, the Europeans reduce their intake of beef, Americans change their toilet paper purchases from Canadian-sourced pulp to recycled? In other words, we have outsourced our resource demands from domestic to foreign sources, but want these resources to be extracted on our terms—something we aren’t even doing ourselves. Can we really have it both ways in a telecoupled world?
President Macron condemns the Brazilians for burning their
(“our”) forests. Who, exactly is
lighting the match?
Image of Match: yaoqi-lai-7iatBuqFvY0-unsplash.jpg
Significance: Mangroves represent a unique ecosystem in
coastal area supporting a rich biodiversity and providing a range of nature’s
contribution to people including provisioning, regulating and supporting,
crucial for the sustenance of local communities. There ecosystem service benefits have been
valued at an average of 4200 US$/hectare/year.*
They provide coastal protection against storms and flooding, are
critical nursery habitats for fish, birds and marine mammals, act as effective
nutrient filters.* South-East Asian mangroves are among the most species
diverse in the world, having 268 plant species including 52 taxa growing
exclusively in mangrove habitat. Mangrove forests and forests soils can also
store significant amounts of organic carbon.*
Status: Recent changes in land use primarily for aquaculture has led to transformation of mangroves (up to 75 per cent in the last 3 decades. Mangroves exist in coastal areas where development demand is high and are being highly threatened by land-use change (see 4.1.2; 4.4.1). An estimated 1,140 km2 of mangroves have been lost between 2000 and 2012 in South-East Asia, with an average rate of 0.7-3.0 per cent per year.
include rapid urbanization (Philippines, Thailand, Vietnam), aquaculture (e.g.,
shrimp farming), paddy farming (Myanmar), expansion of oil palm (Malaysia and
Indonesia, including new development in Papua) (See
Figure above and chart below) In Asia, more than 50 per cent of
mangroves have been lost to support aquaculture, with 40 per cent of mangroves
in the Philippines lost to agriculture.
Indirect anthropogenic changes include those related to climate change—drought (e.g., Gulf of Carpentaria, Australia Nov-Dec 2016); rising sea levels pose a threat to mangroves in Bangladesh, New Zealand, Vietnam and China. Loss of mangrove forests and soils also removes carbon storage; Indonesia, Malaysia and Myanmar contributed 77% of global mangrove organic carbon storage loss between 2000-2015.*
*Source: Jonathan Sanderman et al 2018 A Global map of mangrove forest soil carbon at 30m resolution. Environ. Res. Lett. 13 055002
The percentage of global population using at least a basic drinking water service rose from 81 to 89% between 2000 and 2015
3 out of 10 (2.1 billion; 29% global population) did not have a safely managed drinking water service in 2015
844 million still lacked even a basic drinking water service
Water-related deaths impact thousands and costs billions
In 2015, an estimated 2.1 billion people lacked access to safely managed drinking water services and 4.5 billion lacked access to safely managed sanitation services. (WWAP)
Almost half of people drinking water from unprotected sources live in Sub-Saharan Africa, where the burden of collecting water lies mainly on women and girls, many of whom spend more than 30 minutes on each trip to collect water. (WWAP)
Worldwide, only 2.9 billion people (39% of global population) used safely managed sanitation services in 2015. 40% of these people lived in rural areas.
2.1 billion people had access to “basic” sanitation services.
2.3 billion (one out of every three people) lacked even a basic sanitation service—nearly 1 billion people (892 million) still practiced open defecation.
The atmospheric abundance
of CO2 has increased by an average of 1.83 ppm per year over the past 40
years (1979-2018). The CO2 increase is accelerating — while it averaged
about 1.6 ppm per year in the 1980s and 1.5 ppm per year in the 1990s, the
growth rate increased to 2.3 ppm per year during the last decade (2009-2018).
The annual CO2 increase from 1 Jan 2018 to 1 Jan 2019 was 2.5 ± 0.1 ppm (see https://www.esrl.noaa.gov/gmd/ccgg/trends/global.html), which is slightly higher than the average
of the previous decade, and much higher than the two decades before that.
Total global carbon dioxide emissions in 2017: 41.2±2.8 GtCO2; 53% increase over 1990 (Source: Global Carbon Project)
Carbon dioxide emissions attributable to land-use change are highly uncertain, with no clear trend in the last decade
Land-use change was the dominant source of annual CO2 emissions until around 1950. In 1960 land-use change emissions accounted for 43% of emissions; between 2008-2017 they averaged 13%. In total, CO2 from land-use change accounts for 31% of cumulative emissions between 1870-2017.
Fossil CO2 emissions now dominate global changes: Coal (32%), Oil (25%), Gas (10%), Others (2%) account for 69% of cumulative emissions between 1870-2017.
Radiative Forcing: 298 times that of CO2 over a 100 year period Residence time: 114 years
Agriculture (soil management—fertilizers, manure, burning of agricultural residues)
Growth of nitrous oxide
Short-Lived Climate Pollutants
Black Carbon: 6600Gg (2015)
Radiative Forcing: Black Carbon (BC) has a strong influence on radiative forcing, affecting the climate globally and regionally, and is responsible for a significant proportion of the global forcing to date.
Bond (2013)* estimated that black carbon, with a total climate forcing of +1.1 W m-2, is the second most important human emission in terms of its climate-forcing in the present-day atmosphere; only carbon dioxide is estimated to have a greater forcing. For comparison, the radiative forcings including indirect effects from emissions of the two most significant long-lived greenhouse gases, carbon dioxide (CO2) and methane (CH4), in 2005 were +1.56 and +0.86 W m-2, respectively.
BC deposited on the cryosphere leads to enhanced melting rates and can affect the intensity and distribution of precipitation. Climate and Clean Air Coalition
Residence Time: 4–12 days
! ! Global emission estimates have uncertainties of about a factor of 2 (i.e., -50% to +100%) or even by a factor of 3 (See Climate and Clean Air Coalition)
Domestic biomass combustion (especially in traditional cookstoves)
Open-burning of municipal solid waste
Crop residue open-burning in the field
Traditional brick kilns
Forest fires and savanna burning
Traditional coke ovens
Flaring from oil gas extraction and processing
Transportation (diesel engines in on-and off-road vehicles, ships, generators)
T. C., Doherty, S. J., Fahey, D. W., Forster, P. M., Berntsen, T., DeAngelo, B.
J., Flanner, M. G., Ghan, S., Kärcher, B., Koch, D., Kinne, S., Kondo, Y.,
Quinn, P. K., Sarofim, M. C., Schultz, M. G., Schul, M., Venkataraman, C.,
Zhang, H., Zhang, S., Bellouin, N., Guttikunda, S. K., Hopke, P. K., Jacobson,
M. Z., Kaiser, J. W., Klimont, Z., Lohmann, U., Schwarz, J. P., Shindell, D.,
Storelvmo, T., Warren, S. G., and Zender, C. S.: Bounding the role of black
carbon in the climate system: A scientific assessment, J. Geophys. Res.-Atmos.,
118, 5380– 5552, https://doi.org/10.1002/jgrd.50171, 2013.
The abundances of the majority of Ozone Depleting Substances (ODSs) that were originally controlled under the Montreal Protocol are now declining, as their emissions are smaller than the rate at which they are destroyed. In contrast, the abundances of most of the replacement compounds, HCFCs and hydrofluorocarbons are increasing. (United Nations Scientific Assessment of Ozone Depletion 2018)
The ozone hole is not technically a “hole” where no ozone is present, but is actually a region of exceptionally depleted ozone in the stratosphere over the Antarctic that happens at the beginning of Southern Hemisphere spring (August–October). Satellite instruments provide us with daily images of ozone over the Antarctic region. The ozone hole image shows the very low values (blue and purple colored area) centered over Antarctica on 4 October 2004. From the historical record we know that total column ozone values of less than 220 Dobson Units were not observed prior to 1979. From an aircraft field mission over Antarctica we also know that a total column ozone level of less than 220 Dobson Units is a result of catalyzed ozone loss from chlorine and bromine compounds. For these reasons, we use 220 Dobson Units as the boundary of the region representing ozone loss. Using the daily snapshots of total column ozone, we can calculate the area on the Earth that is enclosed by a line with values of 220 Dobson Units (the white line in the figure). Source: NASA Ozone Watch
The 2018 ozone hole: The polar vortex began to form in early May and reached its maximum area in late September at around 34 million square kilometres. It was a little larger than the decadal mean in size, and was generally of average or above average stability. The ozone hole grew rapidly and by its maximum in late September was above the average size for the decade at 24.8 million square kilometres. The area with ozone hole values had declined to zero by the end of November, later than in the last two years, but sooner than the decadal average. NASA observations show that a minimum ozone amount of 102 DU was reached on October 11 and 12. Although this is a low value it is not as low as around 1990 to 2000. Ozone depletion would have been much worse this year without the protection of the Montreal Protocol.
Although the amount of ozone destroying substances in the atmosphere is going down, the inter-annual variation in the size and depth of the ozone hole is largely controlled by the meteorological conditions in the stratosphere.
A simple extrapolation of the trend in minimum values gives the final year with ozone hole levels as 2073, though the error bars on this estimate are very large. Models suggest that recovery may be more rapid after 2010.
It is still too soon to say that we have had the worst ever ozone hole, particularly as there has been no major volcanic eruption in the Southern Hemisphere since 1992. There has also been little cooling of the lower stratosphere since the mid 1990s.
Observations reported in Nature in May 2018 showed that the rate of decline of CFC-11, an ozone
depleting substances in the atmosphere, which is also a greenhouse gas, had
become slower than predicted. This suggested that either something
unusual was taking place in the atmosphere or that there were additional
man-made emissions. The paper suggested that the most likely reason was
illegal manufacture and release from somewhere in eastern Asia. Investigation by the EIA has found that production of polyurethene foam in
China can explain the observed changes. They encourage the Chinese
government to take immediate action. This became news again in May 2019
when another paper was published in Nature.
CFC’s—refrigerants; decompose in the
upper atmosphere and catalyze the destruction of ozone. Phased out according to the provisions of the
1990 Montreal Protocols of 1987, 1990.
HFC’s and HCFC’s—Substitutes for
CFC’s. HCFC to be phased out by 2040
because they destroy ozone. HFC’s
targeted for emission reductions in the
CFC’s—100 years (CFC-12)
HFC’s –13 years (e.g., HFC-134a);
lifetime weighted by usage—15 years
Ozone Depleting Gas Index (ODGI) Source: NOAA ODGI
The ODGI is estimated directly from
observations at Earth’s surface of the most abundant long-lived, chlorine and
bromine containing gases regulated by the Montreal Protocol (15 individual
chemicals). These ongoing, surface-based observations provide a direct measure
of the total number of chlorine and bromine atoms in the lower atmosphere, or
troposphere, contained in chemicals with lifetimes longer than approximately
0.5 yr. Because the lower atmosphere is quite well-mixed, these observations
also provide an accurate estimate of the composition of air entering the
stratosphere. The threat to stratospheric ozone from ODSs, however, is derived
only after considering additional factors: the time it takes for air to be transported
from the troposphere to different regions of the stratosphere, air mixing
processes during that transport, and the rate at which ODSs photolytically
degrade and liberate reactive forms of chlorine and bromine in the
2018 Antarctic ODGI 79;
i.e., we have progressed 21% towards the 1980 benchmark
2018 Mid-latitude ODGI
55; i.e., we have progressed 45% towards the 1980 benchmark
Particulates and Ozone
Matter (PM2.5) Air Quality
matter contains microscopic solids or liquid droplets that are so small that
they can be inhaled and cause serious health problems. Some particles less
than 10 micrometers in diameter can get deep into your lungs and some may even
get into your bloodstream. Of these, particles less than
2.5 micrometers in diameter, also known as fine particles or PM2.5,
pose the greatest risk to health.( EPA
particles are small enough to work their way deep into the lungs and into the
bloodstream, where they trigger heart attack, stroke, lung cancer and asthma (Berkeley Earth
Get the Airvisual 2018 World Air Quality Report Here
pollution kills more people worldwide each year than does AIDS, malaria,
diabetes or tuberculosis.
the United States and Europe, air pollution is equivalent in detrimental health
effects to smoking 0.4 to 1.6 cigarettes per day.
China the numbers are far worse; on bad days the health effects of air
pollution are comparable to the harm done smoking three packs per day (60
cigarettes) by every man, woman, and child.
“Studies of emission inventories show that, of the major pollutants, the lowest uncertainties are associated with CO2 and SO2,which depend primarily on the quality of fossil fuel statistical data and fuel properties. Studies estimate globally an 8% uncertainty (90% confidence interval) for emissions of CO2 (Andres et al., 2012; IPCC, 2014) and 8–14% uncertainty for SO2, for a roughly 5–95% confidence interval (Smith et al., 2011). However, uncertainty for certain sectors can be much larger, for example 50% for global estimates of CO2 emissions from the combined Agriculture, Forestry and Other Land Use sector (IPCC, 2014). Similarly, uncertainty can be larger in certain regions (e.g. China) due to uncertainties in the level of coal consumption, emission factor for coal and the actual implementation and efficiency of control technology (Guan et al., 2012; Liu et al., 2015; Olivier et al., 2015; Xu et al., 2009; Zhang et al., 2012). Uncertainties for global inventories of GHGs other than CO2 are much higher, being estimated by IPCC (2014) at ±20% for CH4 and ±60% for N2O (both expressed as the 90% confidence interval). Again, uncertainties for some sectors are much higher, for example, for CH4 emissions from rice paddy fields, livestock enteric fermentation and landfill.
Emissions of PM, including BC and primary OC, are more uncertain, as these pollutants usually form under poor combustion conditions in small, inefficient installations burning poor-quality fuels, which are difficult to account for, resulting in large emission variability (Bond et al., 2004; Klimont et al., 2017; Hoesly et al., 2018). Considering local data and knowledge about emission sources and their emission factors could significantly reduce these uncertainties (Zhang et al., 2009). Inconsistencies in measurements of PM emissions (e.g. in-stack or directly after stack for industry; laboratory versus real- world measurements for cookstoves) in different countries contribute to overall global inventory uncertainties. Uncertainty can also be large for activity data of relevance to PM emissions – such as poor-quality fuels (e.g. biomass) in cook stoves or brick kilns (Klimont et al 2017) or even size and composition of local vehicle fleets.
Bond et al. (2004) estimated total uncertainties of about a factor of 2 (i.e. -50% to +100%) in their global estimates of BC and OC emissions for 1996 from contained combustion (excluding open-burning of vegetation and crop residues). More recent work (Bond et al., 2013) estimated larger uncertainties for a global BC inventory for the year 2000; of around a factor of 3 for energy-related emissions and >3 when open-burning is included.Advances in emission characterization for small residential, industrial, and mobile sources will be required to reduce the scale of these uncertainties. Uncertainties in national scale BC emission estimates are likely to be less than for the global inventories described above. For example, emission uncertainties are considered to be in the order of 1.5 to 2-fold for national BC inventories recently prepared by EU countries for CLRTAP.” (Emphasis added)
This is an example post, originally published as part of Blogging University. Enroll in one of our ten programs, and start your blog right.
You’re going to publish a post today. Don’t worry about how your blog looks. Don’t worry if you haven’t given it a name yet, or you’re feeling overwhelmed. Just click the “New Post” button, and tell us why you’re here.
Why do this?
Because it gives new readers context. What are you about? Why should they read your blog?
Because it will help you focus you own ideas about your blog and what you’d like to do with it.
The post can be short or long, a personal intro to your life or a bloggy mission statement, a manifesto for the future or a simple outline of your the types of things you hope to publish.
To help you get started, here are a few questions:
Why are you blogging publicly, rather than keeping a personal journal?
What topics do you think you’ll write about?
Who would you love to connect with via your blog?
If you blog successfully throughout the next year, what would you hope to have accomplished?
You’re not locked into any of this; one of the wonderful things about blogs is how they constantly evolve as we learn, grow, and interact with one another — but it’s good to know where and why you started, and articulating your goals may just give you a few other post ideas.
Can’t think how to get started? Just write the first thing that pops into your head. Anne Lamott, author of a book on writing we love, says that you need to give yourself permission to write a “crappy first draft”. Anne makes a great point — just start writing, and worry about editing it later.
When you’re ready to publish, give your post three to five tags that describe your blog’s focus — writing, photography, fiction, parenting, food, cars, movies, sports, whatever. These tags will help others who care about your topics find you in the Reader. Make sure one of the tags is “zerotohero,” so other new bloggers can find you, too.