….Is [freshwater] also soaking up atmospheric carbon?A new paper published in Current Biology presents some of the first evidence that the answer may be yes, but perhaps not the same way as occurs in the ocean.
In the new study researchers reported a significant increase of CO2 and a correlating pH decrease of about 0.3 in four reservoirs in Germany over 35 years. They analyzed data collected from 1981 to 2015 by the local Ruhr region agency that monitors drinking water, and were able to document the rising carbon dioxide levels over time by factoring in changes in temperature, water density, pH, ion species distribution and total inorganic content….
…A crucial reason why the study of freshwater acidification has lagged until now is because determining how atmospheric carbon affects these ecosystems requires complex modeling…
…The primary way freshwater ecosystems absorb CO2 created by humans burning fossil fuels is likely different than what happens in oceans. In lakes and reservoirs the extra atmospheric CO2 feeds the surrounding vegetation and the rising global temperature lengthens the growing season. As plants in and around the lake grow larger and/or proliferate, the amount of organic carbon available when they die and the rate at which they break down in soil increases. Precipitation then washes it into lakes and other freshwater systems….
Linda C. Weiss, Leonie Pötter, Annika Steiger, Sebastian Kruppert, Uwe Frost, Ralph Tollrian. Rising pCO 2 in Freshwater Ecosystems Has the Potential to Negatively Affect Predator-Induced Defenses in Daphnia. Current Biology, 2018; DOI: 10.1016/j.cub.2017.12.022
Soils hold the largest biogeochemically active terrestrial carbon pool on Earth and are critical for stabilizing atmospheric CO2 concentrations. Nonetheless, global pressures on soils continue from changes in land management, including the need for increasing bioenergy and food production
Soil organic matter (SOM) anchors global terrestrial productivity and food and fiber supply. SOM retains water and soil nutrients and stores more global carbon than do plants and the atmosphere combined. SOM is also decomposed by microbes, returning CO2, a greenhouse gas, to the atmosphere. Unfortunately, soil carbon stocks have been widely lost or degraded through land use changes and unsustainable forest and agricultural practices.
To understand its structure and function and to maintain and restore SOM, we need a better appreciation of soil organic carbon (SOC) saturation capacity and the retention of above- and belowground inputs in SOM. Our analysis suggests root inputs are approximately five times more likely than an equivalent mass of aboveground litter to be stabilized as SOM. Microbes, particularly fungi and bacteria, and soil faunal food webs strongly influence SOM decomposition at shallower depths, whereas mineral associations drive stabilization at depths greater than ∼30 cm. Global uncertainties in the amounts and locations of SOM include the extent of wetland, peatland, and permafrost systems and factors that constrain soil depths, such as shallow bedrock. In consideration of these uncertainties, we estimate global SOC stocks at depths of 2 and 3 m to be between 2,270 and 2,770 Pg, respectively, but could be as much as 700 Pg smaller. Sedimentary deposits deeper than 3 m likely contain > 500 Pg of additional SOC. Soils hold the largest biogeochemically active terrestrial carbon pool on Earth and are critical for stabilizing atmospheric CO2 concentrations. Nonetheless, global pressures on soils continue from changes in land management, including the need for increasing bioenergy and food production
Excerpts on future directions:
2.1. Emerging Research Questions for Plant Production, Allocation, and SOM:
1. What is the relative contribution of roots compared with that of litter inputs to the accumulation of SOM under different vegetation types, soil conditions, land uses, and climates?
2. Is the higher CUE of root litter compared with that of aboveground litter explained by differences in chemical composition or root-soil interactions?
3. What is the fate of nutrients such as nitrogen and phosphorus from aboveground and belowground organic matter respired during decomposition, and what is their role in SOM formation?
4. In consideration of trade-offs with production, how feasible is it to manage plant allocation patterns in managed landscapes to sequester SOM but maintain growth and yield?
3.1. Emerging Research Questions for Belowground Food Webs and Soil Ecology
Although it is well established that microbes and soil fauna exert strong controls on the rates and pathways of plant litter decay, their role in soil carbon stabilization is less clear. Mycorrhizae have a strong role in carbon stabilization in many ecosystems, but the relative role of fungi in soil carbon stabilization, compared with that of bacteria, is not well characterized. Several questions deserve particular attention:
1. How critical is understanding microbial physiology to predicting future changes in soil carbon stocks with climate change?
2. Will microbial CUE be altered by global warming, will thermal adaptation occur, or will broad changes in the microbial community lead to unexpected changes in soil carbon stabilization patterns?
3. How will changes in future vegetation patterns affect detrital inputs to soil and the stabilization of these inputs?
4. Do soil fauna need to be added to models of SOM that include microbes?
4.1. Emerging Research Questions for Biotic–Abiotic Interactions and SOM
1. How will interactions between biotic processes (e.g., NPP, detrital inputs, and microbial activity) and carbon retention on mineral surfaces be altered by climate change?
2. Do soil minerals and their interactions with biotic processes need to be included in future SOM models?
3. How can abiotic and biotic factors be incorporated into land surface and Earth system models to reduce future uncertainty?
5.3. Emerging Research Questions for Global SOM Stocks, Distributions, and Controls:
Answers to the following important research questions could help close the data gap:
1. How can we better constrain the distributions of peatland and permafrost systems, the amount of SOC and SON they contain, and their vulnerability to a warming climate?
2. How can computational approaches enhance our understanding of depth distributions for SOM and their biotic and abiotic controls?
3. How can we best improve and verify estimates of bedrock depth and its influence on the global content of SOC and SON?
Soil carbon is vulnerable to oxidation and release to the atmosphere through a variety of human activities (Figure 1), including land use disturbance and the effects of climate change. The greatest human-induced loss of SOC has come from the conversion of native forests and grasslands to annual crops (Paustian et al. 1997, Lal 2004). Understanding the role of agricultural management on SOC stocks is therefore critical both for predicting future carbon fluxes and for devising best-management strategies to mitigate and reverse soil loss…. Mitigating and even reversing these land use effects, however, are both possible and desirable (Minansy et al. 2017)….. The initial status of the land is critical to the interpretation of afforestation studies. A degraded system often gains SOM with afforestation or other management; a healthy, native ecosystem may sometimes lose it….
….The adoption of soil conservation practices such as reduced tillage, improved residue management, reduced bare fallow, and conservation reserve plantings has stabilized, and partially reversed, SOC loss in North American agricultural soils (Paustian et al. 2016)….Improved grazing management, fertilization, sowing legumes, and improved grass species are additional ways to increase soil carbon by as much as 1 Mg C ha−1year−1 (Conant et al. 2017)…
….Ecosystem and Earth system models can improve their representations of SOM by adding modifiers and microbial attributes that influence SOM formation and stabilization across scales….
….Over the next century, most projected land use change is expected to arise from repurposing existing agricultural land rather than clearing native forests (Watson et al. 2014). Emerging land use activities that combine carbon sequestration with crop production offer great promise to increase global SOM while sustainably meeting food and fiber production for an increasing human population (Francis et al. 2016).
….anthropogenic greenhouse gas emissions have altered the planet’s climate, including
temperatures, precipitation, and vapor pressure deficit, and will continue to do so. Additional changes are apparent in the patterns and extremes of weather and in the frequency, intensity, and severity of disturbances. All the factors, knowledge, and skill illustrated through the examples in this review will be needed to project the effects of climate change on SOM. Global pressures on soils are coming from continuing changes in land management, such as the need for increasing bioenergy and food production. For these reasons and more, furthering progress in experiments, synthesis, and modeling of SOM will remain a research priority for decades..
Other links to aggregated content on soil science, carbon sequestration and range science:
The climate change simulations that best capture current planetary conditions are also the ones that predict the most dire levels of human-driven warming, according to a statistical study released in the journal Nature on Wednesday.
The study, by Patrick Brown and Ken Caldeira of the Carnegie Institution for Science in Stanford, California, examined the high-powered climate change simulations, or models, that researchers use to project the future of the planet based on the physical equations that govern the behavior of the atmosphere and oceans….
….Lead study author Brown argued, though, that the results have a major real-world implication: They could mean the world can emit even less carbon dioxide than we thought if it wants to hold warming below the widely accepted target of 2 degrees Celsius (3.6 degrees Fahrenheit). This would mean shrinking the “carbon budget.”
The study “would imply that to stabilize temperature at 2 degrees Celsius, you’d have to have 15 percent less cumulative CO2 emissions,” he said.
Scientists have evidence that El Niño boosts CO2 levels, and they are pinning down how
As a carbon booster, El Niño could hasten rising temperatures, bringing the world to dangerous thresholds sooner than thought. It could also enhance feedbacks between climate and vegetation that could reduce plants’ ability to absorb CO2 in non-Niño years as well. If bad droughts or wildfires kill many trees, for example, forests and their carbon sequestering potential may take centuries to recover, if ever.
Every two to seven years, abnormally warm water in the Pacific Ocean causes an atmospheric disturbance called El Niño. It often makes extreme weather worse in various places around the world: greater floods, tougher droughts, more wildfires. Now scientists have new evidence indicating El Niño conditions might also add extra carbon dioxide to the atmosphere as well as lessen the ability of trees to absorb the greenhouse gas…
….A recent article in Science about satellite measurements made during El Niño by NASA’s Orbiting Carbon Observatory-2 showed most of the extra CO2 originated in the tropics. It also suggested each tropical region contributed a similar amount of CO2 as in other strong El Niño years, each in its own way. In South America’s Amazon, for example, slower-growing plants absorbed less CO2, whereas in Africa, plants and soils released more of the gas….
If left to its own devices, this carbon-rich water remains below ground for hundreds to thousands of years before surfacing in oceans or freshwater bodies. But humans are now extracting groundwater at an unprecedented pace to sustain a growing population
Humans may be adding large amounts of carbon dioxide to the atmosphere by using groundwater faster than it is replenished, according to new research. This process, known as groundwater depletion, releases a significant amount of carbon dioxide into the atmosphere that has until now been overlooked by scientists in calculating carbon sources, according to the new study.
The study’s authors estimate groundwater depletion in the United States could be responsible for releasing 1.7 million metric tons (3.8 billion pounds) of carbon dioxide to the atmosphere every year.
Based on these figures, groundwater depletion should rank among the top 20 sources of carbon emissions documented by the US Environmental Protection Agency (EPA) and the Intergovernmental Panel on Climate Change (IPCC). This would mean the carbon dioxide emitted through groundwater depletion is comparable to the carbon generated from aluminum, glass, and zinc production in the United States, according to the study’s authors….
…Rain falling from the sky contains the same amount of carbon dioxide as is present in the atmosphere. But soil carbon dioxide levels are up to 100 times greater than carbon dioxide levels in the atmosphere, because soil microbes degrade organic carbon into carbon dioxide. When rainwater hits the ground and percolates through Earth’s rocks and sediments, the water dissolves extra carbon produced by these microbes.
If left to its own devices, this carbon-rich water remains below ground for hundreds to thousands of years before surfacing in oceans or freshwater bodies. But humans are now extracting groundwater at an unprecedented pace to sustain a growing population….
…Groundwater depletion’s impact on carbon emissions is significant yet relatively small compared to the leading contributors, according to the authors. For example, scientists estimate fossil fuel combustion in the United States is responsible for releasing more than 5 billion metric tons (11 trillion pounds) of carbon dioxide into the atmosphere every year, close to 3,000 times the amount released from groundwater depletion. Still, the study authors argue that understanding all sources of carbon dioxide emissions is important for making accurate climate change projections and finding solutions….
Warren W. Wood, David W. Hyndman. Groundwater Depletion: A Significant Unreported Source of Atmospheric Carbon Dioxide. Earth’s Future, 2017; DOI:10.1002/2017EF000586
CO2 could soon reach levels that, it’s widely agreed, will lead to catastrophe.
Carbon dioxide removal technology represents either the ultimate insurance policy or the ultimate moral hazard.
It’s been calculated that to equilibrate to current CO2 levels the planet still needs to warm by half a degree. And every ten days another billion tons of carbon dioxide are released.
….This past April, the concentration of carbon dioxide in the atmosphere reached a record four hundred and ten parts per million. The amount of CO2 in the air now is probably greater than it’s been at any time since the mid-Pliocene, three and a half million years ago, when there was a lot less ice at the poles and sea levels were sixty feet higher. This year’s record will be surpassed next year, and next year’s the year after that. Even if every country fulfills the pledges made in the Paris climate accord—and the United States has said that it doesn’t intend to—carbon dioxide could soon reach levels that, it’s widely agreed, will lead to catastrophe, assuming it hasn’t already done so.
Carbon-dioxide removal is, potentially, a trillion-dollar enterprise because it offers a way not just to slow the rise in CO2 but to reverse it. The process is sometimes referred to as “negative emissions”: instead of adding carbon to the air, it subtracts it. Carbon-removal plants could be built anywhere, or everywhere. Construct enough of them and, in theory at least, CO2 emissions could continue unabated and still we could avert calamity. Depending on how you look at things, the technology represents either the ultimate insurance policy or the ultimate moral hazard…
…still more warming is locked in. There’s so much inertia in the climate system, which is as vast as the earth itself, that the globe has yet to fully adjust to the hundreds of billions of tons of carbon dioxide that have been added to the atmosphere in the past few decades. It’s been calculated that to equilibrate to current CO2 levels the planet still needs to warm by half a degree. And every ten days another billion tons of carbon dioxide are released. Last month, the World Meteorological Organization announced that the concentration of carbon dioxide in the atmosphere jumped by a record amount in 2016….
…Experts I spoke to said that the main reason C.C.S. (carbon capture and storage) hasn’t caught on is that there’s no inducement to use it. Capturing the CO2 from a smokestack consumes a lot of power—up to twenty-five per cent of the total produced at a typical coal-burning plant. And this, of course, translates into costs. What company is going to assume such costs when it can dump CO2 into the air for free?…
….the United Nations Environment Programme released its annual Emissions Gap Report [that called] the difference between the emissions reductions needed to avoid dangerous climate change and those which countries have pledged to achieve as “alarmingly high.” For the first time, this year’s report contains a chapter on negative emissions. “In order to achieve the goals of the Paris Agreement,” it notes, “carbon dioxide removal is likely a necessary step.”
As a technology of last resort, carbon removal is, almost by its nature, paradoxical. It has become vital without necessarily being viable. It may be impossible to manage and it may also be impossible to manage without. ♦
Upstream emissions may occur anywhere in the world and are roughly equal in size to the total emissions originating from a city’s own territory, a new study shows.
Cities should be encouraged and enabled to focus on their full emission spectrum — local and upstream — as they continue to develop their climate mitigation plans.
Among the cities studied, Berlin’s global hinterland is largest, with more than half of its upstream emissions occurring outside of Germany, mostly in Russia, China and across the European Union.
20% of Mexico City’s considerably smaller upstream emissions occur outside Mexico, mainly in the US and China.
November 7, 2017 Potsdam Institute for Climate Impact Research (PIK)
Greenhouse gas emissions caused by urban households’ purchases of goods and services from beyond city limits are much bigger than previously thought. These upstream emissions may occur anywhere in the world and are roughly equal in size to the total emissions originating from a city’s own territory, a new study shows. This is not bad news but in fact offers local policy-makers more leverage to tackle climate change, the authors argue in view of the UN climate summit COP23 that just started…
…The planned emission reductions presented so far by national governments at the UN summit are clearly insufficient to limit global warming to well below 2 degrees Celsius, the target agreed by 190 countries, therefore additional efforts are needed.“
…If a city instead chooses to foster low carbon construction materials this can drastically reduce its indirect CO2 emissions. Even things that cities are already doing can affect far-away emissions. Raising insulation standards for buildings for example certainly slashes local emissions by reducing heating fuel demand. Yet it can also turn down the need for electric cooling in summer which reduces power generation and hence greenhouse gas emissions in some power plant beyond city borders.
…By choosing energy from solar or wind, city governments could in fact close down far-away coal-fired power plants….
In 2017, CO2 emissions from fossil fuels and industry are projected to grow by 2% (0.8% to 3%). This follows three years of nearly no growth (2014-2016). (GDP to rise 3.6% according to IMF figures).
Global CO2 emissions from all human activities are set to reach 41 billion tonnes (41 Gt CO2) by the end of 2017. Meanwhile emissions from fossil fuels are set to reach 37 Gt CO2 — a record high.
Atmospheric CO2 concentration reached 403 parts per million in 2016, and is expected to increase by 2.5 ppm in 2017.
[and some good news] CO2 emissions decreased in the presence of growing economic activity in 22 countries representing 20 per cent of global emissions; Renewable energy has increased rapidly at 14% per year over the last five years — albeit from a very low base.
Global carbon emissions are on the rise again in 2017 after three years of little to no growth. Global emissions from all human activities will reach 41 billion tons in 2017, following a projected 2 percent rise in burning fossil fuels. It was hoped that emissions might soon reach their peak after three stable years, so this is an unwelcome message for policy makers and delegates at the UN Climate Change Conference (COP 23) in Bonn this week.
The research, published today simultaneously in the journals Nature Climate Change, Earth System Science Data Discussions and Environmental Research Letters, reveals that global emissions from all human activities will reach 41 billion tonnes in 2017, following a projected 2% rise in burning fossil fuels.
The figures point to China as the main cause of the renewed growth in fossil emissions — with a projected growth of 3.5%.
CO2 emissions are expected to decline by 0.4% in the US and 0.2% in the EU, smaller declines than during the previous decade.
Increases in coal use in China and the US are expected this year, reversing their decreases since 2013….
….[some good news] CO2 emissions decreased in the presence of growing economic activity in 22 countries representing 20 per cent of global emissions….
Glen P. Peters et al. Towards real-time verification of CO2 emissions. Nature Climate Change, 2017; DOI: 10.1038/s41558-017-0013-9
limiting the increase in global average temperatures above pre-industrial levels to 1.5°C is not yet geophysically impossible, but likely requires more ambitious emission reductions than those pledged so far
Contrary to many other studies, this finds we have more than 700 billion tons left to emit to keep warming within 1.5 degrees Celsius, with a two-thirds probability of success. “That’s about 20 years at present-day emissions
Assuming emissions peak and decline to below current levels by 2030, and continue thereafter on a much steeper decline, which would be historically unprecedented but consistent with a standard ambitious mitigation scenario (RCP2.6), results in a likely range of peak warming of 1.2–2.0°C above the mid-nineteenth century.
limiting warming to 1.5°C is not yet a geophysical impossibility, but is likely to require delivery on strengthened pledges for 2030 followed by challengingly deep and rapid mitigation
[Scientists] investigated the geophysical likelihood of limiting global warming to “well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C.” …the paper concludes that limiting the increase in global average temperatures above pre-industrial levels to 1.5°C, the goal of the Paris Agreement on Climate Change, is not yet geophysically impossible, but likely requires more ambitious emission reductions than those pledged so far….
….’This paper shows that the Paris goals are within reach, but clarifies what the commitment to ‘pursue efforts to limit the temperature increase to 1.5°C’ really implies. Starting with the global review due next year, countries have to get out of coal and strengthen their existing targets so as to keep open the window to the Paris goals. The sooner global emissions start to fall, the lower the risk not only of major climatic disruption, but also of the economic disruption that could otherwise arise from the need for subsequent reductions at historically unprecedented rates, should near-term action remain inadequate.’…
A group of prominent scientists on Monday created a potential whiplash moment for climate policy, suggesting that humanity could have considerably more time than previously thought to avoid a “dangerous” level of global warming. The upward revision to the planet’s influential “carbon budget” was published by a number of researchers who have been deeply involved in studying the concept, making it all the more unexpected. But other outside researchers raised questions about the work, leaving it unclear whether the new analysis — which, if correct, would have very large implications — will stick.In a study published in the journal Nature Geoscience, a team of 10 researchers, led by Richard Millar of the University of Oxford, recalculated the carbon budget for limiting the Earth’s warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above temperatures seen in the late 19th century. It had been widely assumed that this stringent target would prove unachievable — but the new study would appear to give us much more time to get our act together if we want to stay below it.
“What this paper means is that keeping warming to 1.5 degrees C still remains a geophysical possibility, contrary to quite widespread belief,” Millar said in a news briefing…..
“It is very hard to see how we could still have a substantial CO2 emissions budget left for 1.5 °C, given we’re already at 1 °C, thermal inertia means we’ll catch up with some more warming even without increased radiative forcing, and any CO2 emissions reductions inevitably comes with reduced aerosol load as well, the latter reduction causing some further warming,” Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany said by email.
…In 2013, the United Nations’ Intergovernmental Panel on Climate Change (IPCC) calculated that humanity could emit about 1,000 more gigatons, or billion tons, of carbon dioxide from 2011 onward if it wanted a good chance of limiting warming to 2 degrees C — launching the highly influential concept of the “carbon budget.”
The allowable emissions or budget for 1.5 degrees C would, naturally, be lower. One 2015 study found they were 200 billion to 400 billion tons. And we currently emit about 41 billion tons per year, so every three years, more than 100 billion tons are gone. No wonder a recent study put the chance of limiting warming to 1.5 degrees C at 1 percent. Peters said that according to the prior paradigm, we basically would have used up the carbon budget for 1.5 degrees Celsius by the year 2022.
That’s what makes the new result so surprising: It finds that we have more than 700 billion tons left to emit to keep warming within 1.5 degrees Celsius, with a two-thirds probability of success. “That’s about 20 years at present-day emissions,” Millar said at the news briefing….
ABSTRACT: The Paris Agreement has opened debate on whether limiting warming to 1.5°C is compatible with current emission pledges and warming of about 0.9°C from the mid-nineteenth century to the present decade. We show that limiting cumulative post-2015 CO2 emissions to about 200GtC would limit post-2015 warming to less than 0.6°C in 66% of Earth system model members of the CMIP5 ensemble with no mitigation of other climate drivers, increasing to 240GtC with ambitious non-CO2 mitigation. We combine a simple climate–carbon-cycle model with estimated ranges for key climate system properties from the IPCC Fifth Assessment Report. Assuming emissions peak and decline to below current levels by 2030, and continue thereafter on a much steeper decline, which would be historically unprecedented but consistent with a standard ambitious mitigation scenario (RCP2.6), results in a likely range of peak warming of 1.2–2.0°C above the mid-nineteenth century. If CO2 emissions are continuously adjusted over time to limit 2100 warming to 1.5°C, with ambitious non-CO2 mitigation, net future cumulative CO2 emissions are unlikely to prove less than 250GtC and unlikely greater than 540GtC. Hence, limiting warming to 1.5°C is not yet a geophysical impossibility, but is likely to require delivery on strengthened pledges for 2030 followed by challengingly deep and rapid mitigation. Strengthening near-term emissions reductions would hedge against a high climate response or subsequent reduction rates proving economically, technically or politically unfeasible.
Drawdown maps, measures, models, and describes the 100 most substantive solutions to global warming. For each solution, we describe its history, the carbon impact it provides, the relative cost and savings, the path to adoption, and how it works. The goal of the research that informs Drawdown is to determine if we can reverse the buildup of atmospheric carbon within thirty years. All solutions modeled are already in place, well understood, analyzed based on peer-reviewed science, and are expanding around the world.
Drawdown is the work of a prominent and growing coalition of geologists, engineers, agronomists, researchers, fellows, writers, climatologists, biologists, botanists, economists, financial analysts, architects, companies, agencies, NGOs, activists, and other experts who draft, model, fact check, review, and validate all text, inputs, sources, and calculations. Our purpose is to provide helpful information and tools to a wide variety of actors who are dedicated to meaningful change: students, teachers, researchers, philanthropists, investors, entrepreneurs, business people, farmers, policymakers, engaged citizens, and more.