Topics Related to Carbon

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Topics Related to Carbon

  1. Carbon Cycle and Global Carbon Budget

Plants use carbon dioxide and sunlight to make their own food and grow. The carbon becomes part of the plant. Plants that die and are buried may turn into fossil fuels made of carbon like coal and oil over millions of years. When humans burn fossil fuels, most of the carbon quickly enters the atmosphere as carbon dioxide.

Carbon dioxide is a greenhouse gas and traps heat in the atmosphere. Without it and other greenhouse gases, Earth would be a frozen world. But humans have burned so much fuel that there is about 30% more carbon dioxide in the air today than there was about 150 years ago, and Earth is becoming a warmer place. In fact, ice cores show us that there is now more carbon dioxide in the atmosphere than there has been in the last 420,000 years.

Global Carbon Budget

The Global Carbon Project was formed to assist the international science community to establish a common, mutually agreed knowledge base supporting policy debate and action to slow the rate of increase of greenhouse gases in the atmosphere. The growing realization that anthropogenic climate change is a reality has focused the attention of the scientific community, policymakers and the general public on the rising concentration of greenhouse gases, especially carbon dioxide (CO2) in the atmosphere, and on the carbon cycle in general.

Initial attempts, through the United Nations Framework Convention on Climate Change and its Kyoto Protocol, are underway to slow the rate of increase of greenhouse gases in the atmosphere. These societal actions require a scientific understanding of the carbon cycle, and are placing increasing demands on the international science community to establish a common, mutually agreed knowledge base to support policy debate and action.

The Global Carbon Project is responding to this challenge through a shared partnership between the International Geosphere-Biosphere Programme (IGBP), the International Human Dimensions Programme on Global Environmental Change (IHDP), the World Climate Research Programme (WCRP) and Diversitas. This partnership constitutes the Earth Systems Science Partnership (ESSP).

Ocean Acidification

Fundamental changes in seawater chemistry are occurring throughout the world’s oceans. Since the beginning of the industrial revolution, the release of carbon dioxide (CO2) from humankind’s industrial and agricultural activities has increased the amount of CO2 in the atmosphere.

The ocean absorbs about a quarter of the CO2 we release into the atmosphere every year, so as atmospheric CO2 levels increase, so do the levels in the ocean. Initially, many scientists focused on the benefits of the ocean removing this greenhouse gas from the atmosphere.  However, decades of ocean observations now show that there is also a downside — the CO2 absorbed by the ocean is changing the chemistry of the seawater, a process called Ocean Acidification.

Impacts of Oceanic Acidification

Ocean acidification is expected to impact ocean species to varying degrees. Photosynthetic algae and seagrasses may benefit from higher CO2 conditions in the ocean, as they require CO2 to live just like plants on land.

On the other hand, studies have shown that a more acidic environment has a dramatic effect on some calcifying species, including oysters, clams, sea urchins, shallow water corals, deep sea corals, and calcareous plankton. When shelled organisms are at risk, the entire food web may also be at risk. Today, more than a billion people worldwide rely on food from the ocean as their primary source of protein.

Carbon Footprint

A carbon footprint is historically defined as the total set of greenhouse gas emissions caused by an individual, event, organisation, or product, expressed as carbon dioxide equivalent. In most cases, the total carbon footprint cannot be exactly calculated because of inadequate knowledge of and data about the complex interactions between contributing processes, especially which including the influence on natural processes storing or releasing carbon dioxide. For this reason, the carbon footprint has been defined as: “A measure of the total amount of carbon dioxide (CO2) and methane (CH4) emissions of a defined population, system or activity, considering all relevant sources, sinks and storage within the spatial and temporal boundary of the population, system or activity of interest, calculated as carbon dioxide equivalent using the relevant 100-year global warming potential (GWP100).”

Greenhouse gases (GHGs) can be emitted through land clearance and the production and consumption of food, fuels, manufactured goods, materials, wood, roads, buildings, transportation and other services. For simplicity of reporting, it is often expressed in terms of the amount of carbon dioxide, or its equivalent of other GHGs, emitted.

Most of the carbon footprint emissions for the average household come from “indirect” sources, i.e. fuel burned to produce goods far away from the final consumer. These are distinguished from emissions which come from burning fuel directly in one’s car or stove, commonly referred to as “direct” sources of the consumer’s carbon footprint.

 

 

Types of Carbon foot Print

There are two types of carbon foot printing. The main types of carbon footprint are:

  1. Organizational Emissions: From all the activities across the organisation, including buildings’ energy use, industrial processes and company vehicles.
  2. Product Emissions: Over the whole life of a product or service, from the extraction of raw materials and manufacturing right through to its use and final reuse, recycling or disposal.

 

What are the activities that can help our Carbon footprint?

  1. Air travel is usually the largest component of the carbon footprint of frequent flyers.
  2. The second most important lifestyle change is to eat less meat, with particular emphasis on meals containing lamb. Cows and sheep emit large quantities of methane, a powerful global warming gas.
  3. Home heating is next. Poorly insulated housing requires large quantities of energy to heat
  4. Reducing the mileage of the average new car from 15,000 to 10,000 miles a year will save more than a tonne of CO2, about 15% of the average person’s footprint.
  5. The energy needed to make a new computer or phone is many times the amount used to power it over its lifetime. Apple says 80% of the carbon footprint of a new laptop comes from manufacturing and distribution, not use in the home.
  6. Within the last couple of years, LEDs (light-emitting diodes) have become cheap and effective. If you have any energy-guzzling halogen lights in your house – many people have them in kitchens and bathrooms – it makes good financial and carbon sense to replace as many as possible with their LED equivalents.

 

Carbon Offsetting

Mitigation of carbon footprints through the development of alternative projects is known as Carbon offsetting. The alternative projects may be the solar, wind, Tidal energy or reforestation.

Carbon sequestration

Carbon sequestration is the long-term storage of carbon in plants, soils, geologic formations, and the ocean. Carbon sequestration occurs both naturally and as a result of anthropogenic activities and typically refers to the storage of carbon that has the immediate potential to become carbon dioxide gas. In response to growing concerns about climate change resulting from increased carbon dioxideconcentrations in the atmosphere, considerable interest has been drawn to the possibility of increasing the rate of carbon sequestration through changes in land use and forestry and also through geoengineering techniques such as carbon capture and storage.

 

Types of Sequestration:

There are number of technologies under investigation for sequestering carbon from the atmosphere. These can be discussed under three main categories:

  1. Ocean Sequestration: Carbon stored in oceans through direct injection or fertilization.
  2. Geologic Sequestration: Natural pore spaces in geologic formations serve as reservoirs for long-term carbon dioxide storage.
  3. Terrestrial Sequestration: A large amount of carbon is stored in soils and vegetation, which are our natural carbon sinks. Increasing carbon fixation through photosynthesis, slowing down or reducing decomposition of organic matter, and changing land use practices can enhance carbon uptake in these natural sinks.
  4. Geologic Sequestration is thought to have the largest potential for near-term application.

 

Soil Carbon and Carbon sequestration

Agricultural soils are among the planet’s largest reservoirs of carbon and hold potential for expanded carbon sequestration (CS), and thus provide a prospective way of mitigating the increasing atmospheric concentration of CO2. It is estimated that soils can sequester around 20 Pg C in 25 years, more than 10 % of the anthropogenic emissions.

At the same time, this process provides other important benefits for soil, crop and environment quality, prevention of erosion and desertification and for the enhancement of bio-diversity.  Land degradation, does not only reduce crop yields but often reduces the carbon content of agro-ecosystems, and may reduce biodiversity.

It is therefore important to identify what important synergies can be found in the area of soil carbon sequestration between the three UN conventions: UNFCC, UNCCD and UNCBD.

 

Farming Practices that help in Carbon sequestration

One of agriculture’s major opportunities to help mitigate the effects of climate-warming gases lies in management of soil to increase organic content, thereby removing carbon from the atmosphere. Many scientists are conducting studies to determine which agricultural practices will in fact sequester carbon.

Recent studies, demonstrate that a number of biological, soil-based practices employed in integrated systems have great potential to sequester carbon. In contrast, recent studies suggest that no-till, a form of conservation tillage, has environmental benefits such as reducing soil erosion, but may not sequester more carbon than conventional tillage (plowing).

 

Can Organic Farming help in Carbon Sequestration?

We could sequester more than 100% of current annual CO2 emissions with a switch to widely available and inexpensive organic management practices, which we term “regenerative organic agriculture.”

If management of all current cropland shifted to reflect the regenerative model as practiced at the research sites included in the white paper, more than 40% of annual emissions could potentially be captured.  If, at the same time, all global pasture was managed to a regenerative model, an additional 71% could be sequestered.  Essentially, passing the 100% mark means a drawing down of excess greenhouse gases, resulting in the reversal of the greenhouse effect.

Regenerative organic agriculture is comprised of organic practices including (at a minimum): cover crops, residue mulching, composting and crop rotation. Conservation tillage, while not yet widely used in organic systems, is a regenerative organic practice integral to soil-carbon sequestration.  Other biological farming systems that use some of these techniques include ecological, progressive, natural, pro-soil, and carbon farming.

How dumping of Iron can Induce Carbon Sequestration?

Dumping iron into the sea can bury carbon dioxide for centuries, potentially helping reduce the impact of climate change, according to a major new study. The work shows for the first time that much of the algae that blooms when iron filings are added dies and falls into the deep ocean.

A team added seven tonnes of iron sulphate to the ocean near Antarctica, where iron levels are extremely low. The addition of the missing nutrient prompted a massive bloom of phytoplankton to begin growing within a week. As the phytoplankton, mostly species of diatom, began to die after three weeks, they sank towards the ocean floor, taking the carbon they had incorporated with them.

A dozen other experiments have shown that iron can prompt phytoplankton blooms, but this is the first study to show that the carbon the plants take up is deeply buried. Other researchers recognise the significance of this but warn of other issues that might prevent the iron fertilisation of the ocean as being a useful geoengineering technique.

Ocean Iron fertilisation could bury at most 1 gigatonne of CO2 per year compared to annual emissions of 8-9Gt, of which 4Gt accumulates in the atmosphere. But sequestering some CO2 could make the difference between crossing a climate “tipping” point, where feedback effects lead to runaway global warming, he said.

Blue Carbon

Blue carbon is the carbon captured by the world’s oceans and coastal ecosystems. The carboncaptured by living organisms in oceans is stored in the form of biomass and sediments from mangroves, salt marshes, seagrasses and potentially algae.

Blue carbon is the carbon stored in coastal and marine ecosystems. The Blue Carbon Initiative currently focuses on carbon in coastal ecosystems – mangroves, tidal marshes and seagrasses. These ecosystems sequester and store large quantities of blue carbon in both the plants and the sediment below. Sea grasses, mangroves, and salt marshes along our coast “capture and hold” carbon, acting as something called a carbon sink.

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