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Can the EU become carbon neutral by 2050? A new strategy from the EU!

Can the EU become carbon neutral by 2050? A new strategy from the EU!

On Wednesday 28 November 2018, the European Commission adopted a strategic long-term vision for a climate neutral economy (net-zero emissions) by 2050!  A Clean Planet for All, tactically released ahead of the 24th Conference of the Parties (COP 24), which will be hosted in Katowice, Poland from 2-14 December, describes seven overarching areas that require action and eight different scenarios that allow the EU to significantly reduce emissions.

The EU is currently responsible for approximately 10% of global greenhouse gas emissions and is looking to become a world leader in the transition towards climate neutrality – a state where the amount of emissions produced is equal to that sequestered [1]. A Clean Planet for All highlights how the EU can reduce its emissions and, in two of the eight scenarios outlined, have a climate neutral economy by 2050.

A Clean Planet for All is a leap toward a climate neutral economy but it does not intend to launch new policies, nor alter the 2030 climate & energy framework and targets that are already in place. Instead, it will use these targets as a baseline while simultaneously setting the direction of EU policies so that they align with the Paris Agreement’s temperature objectives, help achieve the UN’s Sustainable Development Goals and improve the EU’s long-term prosperity and health.

What role did science play in the Clean Planet for All strategy?

Reports generated using climate research, such as the IPCC’s Special Report on Global Warming of 1.5ºC, have been catalysts in national climate strategies and policies around the world. This is holds true for the EU’s A Clean Planet for All which features quotes and statistics from the IPCC’s 1.5ºC Report.

International treaties and targets set by organisations such as the United Nations also put pressure on national and regional governments to act and implement their own polices to reduce emissions. Many of these treaties and global targets are based on scientific reports that describe the current state of the world and give projections based on future scenarios. One of the most noteworthy examples of a global treaty is the Paris Agreement which was ratified by 181 counties in 2015. The Sustainable Development Goals are an example of global targets created using a breadth of scientific studies and that are a major consideration when national and local governments are creating policy.

More directly, A Clean Planet for All’s eight different scenarios and their likely outcomes required a huge amount of research and calculations – these scenarios are outlined in more detail below. External scientific input was also employed with scientists and other stakeholders given the opportunity to contribute to the proposal. An EU Public Consultation was open from 17 July until 9 October 2018 and received over 2800 responses. There was also a stakeholder event on 10-11 July 2018 that brought together stakeholders from research, business and the public to discuss the issues with the upcoming strategy.

The 7 strategic building block for a climate neutral economy

A Clean Planet for All outlines seven building blocks that will enable Europe to reduce emissions and build a climate neutral economy.

  1. Energy efficiency
  2. Renewable energy
  3. Clean, safe and connected mobility
  4. Competitive industry and circular economy
  5. Infrastructure and interconnections
  6. Bio-economy and natural carbon sinks
  7. Carbon capture and storage

Figure 1: Achieving a climate neutral economy will require changes in all sectors. Source: EU Commission [3]

Scenarios toward climate neutrality

The Clean Planet for All strategy describes eight different scenarios or pathways that range from an 80% cut in emissions to net-zero emissions by 2050 (see Figure 2 below). Regardless of the scenario chosen, the Commissioner for Climate Action and Energy, Miguel Arias Cañete, emphasised that the structure of the strategy will give member states a certain amount of flexibility to follow different paths. The eight options outlined in the strategy are “what if-scenarios”. They highlight what is likely to happen with a given combination of technologies and actions. While all eight scenarios will enable the EU to reduce emissions, only the last two (shown in the figure below) provide Europe with the opportunity to build a carbon neutral economy by 2050.

The first five scenarios all focus on initiatives which foster a transition towards a climate neutral economy with the extent that electrification, hydrogen, e-fuels and energy efficiency is implemented and the role that the circular economy will play, being the variable. The anticipated electricity consumption required in 2050 also differs depending on the option selected. The energy efficiency and circular economy options have a greater focus on reducing the energy demand rather than developing new sources of clean energy and therefore require the lowest increase in electricity generation (approximately 35% more by 2050 compared with today). Despite the differences, the first five scenarios will all only achieve 80 – 85% emission reductions by 2050 compared with 1990, 15% short of a climate neutral economy.

The sixth scenario combines the first five options but at lower levels and reaches an emissions reduction of up to 90%. The seventh and eighth scenarios are the only ones that could lead to net-zero emissions by 2050. The seventh option combines the first four options and negative emissions technology such as carbon capture and storage. The eighth scenario builds on the seventh with an additional focus on circular economy, encouraging less carbon intensive consumer choices and strengthened carbon sinks via land use changes.

Figure 2: Overview of A Clean Planet for All’s 8 different scenarios to a climate neutral economy [3]

What about the economic cost?

The EU has allocated approximately 20% of its overall 2014-2020 budget (over €206 billion) to climate change-related action. This covers areas such as research and innovation, energy efficiency, public transport, renewable energy, network infrastructure, just to name a few. To achieve a climate neutral economy by 2050, the EU has proposed to raise the share spent on climate-related action to 25% (€320 billion) for the 2021-2027 period.

This is a significant increase but it’s also a smart investment! Not only will it help the EU reach net-emissions but it’s also expected to lower energy bills, increase competitiveness and stimulate economic growth with an estimated GDP increase of up to 2% by 2050. It will also help to reduce the financial impacts of climate change such as damages from increased flooding, heatwaves and droughts. According to a study published in 2018 by the Joint Research Centre, 3ºC of warming (likely in a business-as-usual scenario), would cut Europe’s GDP by at least €240 billion annually by the end of the century. That estimate drops to €79 billion with 2ºC of warming.

Fighting for a climate neutral economy is is expected to have a net-positive impact on employment but of course, some sectors and regions will see job losses. However, the EU has already outlined programmes to manage this issue, such as the European Social Fund Plus (ESF+), and the European Globalisation Adjustment Fund (EGF). As Miguel Arias Cañete (Commissioner for Climate Action and Energy), states:

“Going climate neutral is necessary, possible and in Europe’s interest.”

What are the next steps?

The strategy and scenarios will be discussed at COP24 and may even provide inspiration for other countries to implement similar strategies. You can keep an eye on COP24 developments by streaming sessions via the UNFCCC live webcast and by using #COP24 on social media.

Although already adopted by the European Commission, A Clean Planet for All still needs input and approval from the European Council, the European Parliament’s Environment Committee, the Committee of the Regions and the Economic and Social Committee. According to the Paris Agreement, all 181 nations must submit their 2030 emissions targets by 2020 so it’s likely that comments from these committees will come in early 2019.

It’s likely that there will also be a number of stakeholder events in 2019, such as Citizens Dialogues that give scientists, businesses, non-governmental organisations and the public the opportunity to share their thoughts and be involved in the process. The EGU will provide updates on relevant opportunities as they arise. To receive these updates you can join the EGU’s database of expertise!

References and further reading

[1] A Clean Planet for all. A European strategic long-term vision for a prosperous, modern, competitive and climate neutral economy

[2] Questions and Answers: Long term strategy for Clean Planet for All 

[3] In-Depth Analysis in Support of The Commission Communication Com(2018) 773

New EU plan comes out fighting for ‘climate neutrality’ by 2050

Factsheet on the Long Term Strategy Greenhouse Gas Emissions Reduction

10 countries demand net-zero emission goal in new EU climate strategy

October GeoRoundUp: the best of the Earth sciences from around the web

October GeoRoundUp: the best of the Earth sciences from around the web

Drawing inspiration from popular stories on our social media channels, major geoscience headlines, as well as unique and quirky research, this monthly column aims to bring you the latest Earth and planetary science news from around the web.

Major story

In October, the UN Intergovernmental Panel on Climate Change (IPCC) released a landmark report and summary statement that detailed the severe consequences for our environment and society if global warming continues unabated. The special report, also known as the SR15, was compiled by 91 authors from 40 countries, and cites more than 6,000 peer-reviewed studies.

“There’s no doubt that this dense, science-heavy, 33-page summary is the most significant warning about the impact of climate change in 20 years,” said Matt McGrath an environment correspondent for BBC News.

The  EGU announced its support of the IPCC report in a statement published last month. In this address, EGU President Jonathan Bamber said: “EGU concurs with, and supports, the findings of the SR15 that action to curb the most dangerous consequences of human-induced climate change is urgent, of the utmost importance and the window of opportunity extremely limited.”

The IPCC was first commissioned to produce this report by the UN Convention on Climate Change following the Paris agreement, where world leaders pledged to limit global warming to well below 2ºC above pre-industrial levels and “pursue efforts” towards 1.5ºC. The goal of the report was to better understand what it would take for the world to successfully meet this 1.5ºC target and what the consequences would be if we are unable to reach this goal.

The report illustrates the two different outcomes that would arise from limiting global warming to 1.5ºC or allowing temperatures to rise to 2ºC.

While a half-degree doesn’t come across like a pronounced difference, the report explains that additional warming by this degree could endanger tens of millions more people across the world with life-threatening heat waves, water shortages, and coastal flooding from sea level rise. This kind of warming would also increase the chances that coral reefs and Arctic sea ice in the summer would disappear. These are just a few of the impacts detailed in the report. Recently, Carbon Brief has also produced an interactive graphic that does a deep dive into how climate change at 1.5ºC, 2ºC and beyond will impact different regions and communities around the world.

It should be noted that while limiting warming to 1.5ºC is the better of the two pathways, it still isn’t optimal. For example, under this warming threshold, the authors of the report project that global  sea levels would still rise, coral reefs would decline by 70-90%, and more than 350 million additional people would be exposed to severe drought.

Furthermore, the report goes on to explain what action (and just how much of it) would be necessary to limit warming to 1.5ºC. An article from the Guardian perhaps put it best: “there’s one simple critical takeaway point: we need to cut carbon pollution as much as possible, as fast as possible.

The report authors emphasise that limiting warming would require a massive international movement to reduce emissions and remove carbon dioxide from the atmosphere; and additionally this effort would need to happen within the next few years to avoid the most severe outcomes. They warn that if greenhouse emissions are still released at their current rate, the Earth’s temperature may reach 1.5ºC some time between 2030 and 2052, and reach more than 3ºC by 2100. Even more so, they concluded that the greenhouse gas reduction actions currently pledged by various countries around the world are still not enough to limit warming to 1.5ºC.

Measures to reach this temperature target include reducing global carbon dioxide emissions by 45% from 2010 levels by 2030, and reach a ‘net-zero’ by 2050. and making dramatic investments in renewable energy. They conclude that 70-35% of the world’s electricity should be generated by renewables like wind and solar power by 2050. By that same time, the coal industry would need to be phased out almost entirely.

Moreover, the authors say that we would need to expand forests and develop technology to suck carbon dioxide from the atmosphere. The report notes that climate action needs to be taken on an individual level as well, such as reducing the amount of meat we eat and time we spend on flying airplanes.

The authors report that we have the technology and means to limit warming by 1.5ºC, but they warn that the current political climate could make reaching this goal less likely.

“Limiting warming to 1.5ºC is possible within the laws of chemistry and physics but doing so would require unprecedented changes,” said Jim Skea, Co-Chair of IPCC Working Group III, in an IPCC press release.

Still have questions about the recent report? The IPCC has released a comprehensive FAQ and Carbon Brief has published an in-depth Q&A that addresses questions such as why the panel released the report, why adaptation is important, what the reaction has been, and what’s next.

What you might have missed

BepiColombo approaching Mercury. Credit: ESA/ATG medialab; Mercury: NASA/JPL

Last month the science media was also abuzz with a series of space agency news. On 20 October, the European-Japanese mission BepiColombo successfully launched from French Guiana, starting its seven-year long journey to Mercury, the smallest and least explored terrestrial planet in the Solar System. The probe is poised to be the third mission to travel to Mercury.

Once it arrives in 2025, the spacecraft will actually separate into two satellites, which will orbit the planet for at least one year. One satellite will investigate Mercury’s magnetic field while the other will take a series of measurements, including collecting data on the planet’s terrain, topography, and surface structure and composition. The researchers involved with the mission hope to learn more about Mercury’s origins and better understand the evolution of our solar system.

While one mission has started its journey, another’s has come to an end. Last month NASA’s planet-hunting Kepler space telescope has officially been retired after running out of fuel. Over its 9-year life span, the telescope has spotted more than 2,600 planets outside our solar system, many of which are possibly capable of sustaining life.

“As NASA’s first planet-hunting mission, Kepler has wildly exceeded all our expectations and paved the way for our exploration and search for life in the solar system and beyond,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington. “Not only did it show us how many planets could be out there, it sparked an entirely new and robust field of research that has taken the science community by storm. Its discoveries have shed a new light on our place in the universe, and illuminated the tantalizing mysteries and possibilities among the stars.”

However, even though Kepler’s planet-scoping days are over, NASA’s new space observatory, the Transiting Exoplanet Survey Satellite (TESS) mission, which launched in April 2018, will continue the search for habitable worlds.

NASA’s Kepler space telescope, shown in this artist’s concept, revealed that there are more planets than stars in the Milky Way galaxy. Image credit: NASA

Links we liked

The EGU story

Earlier in October, we announced the winners of the 2019 EGU awards and medals: 45 individuals who have made significant contributions to the Earth, planetary and space sciences and who will be honoured at the 2019 EGU General Assembly next April. We have also announced the winners of the Outstanding Student Poster and PICO (OSPP) Awards corresponding to the 2018 General Assembly, which you can find on our website. Congratulations to all!

This month, we also opened the call for abstracts for the EGU 2019 General Assembly. If you are interested in presenting your work in Vienna in April, make sure you submit your abstract by 10 January 2019, 13:00 CET. If you would like to apply for a Roland Schlich travel grant to attend the meeting, please submit your abstract no later than 1 December 2018. You can find more information on the EGU website.

Interested in science and art? After successfully hosting a cartoonist and a poet in residence at last year’s annual meeting, we are now opening a call for artists to apply for a residency at the EGU 2019 General Assembly. The deadline for applications is 1 December. You can find more information about the opportunity online here.

And don’t forget! To stay abreast of all the EGU’s events and activities, from highlighting papers published in our open access journals to providing news relating to EGU’s scientific divisions and meetings, including the General Assembly, subscribe to receive our monthly newsletter.

Geosciences Column: The quest for life on Mars

Geosciences Column: The quest for life on Mars

Understanding where we come from and whether Earth is the only habitable planet in the Solar System has been a long standing conundrum in science. Partly because it is our nearest neighbour, partly because of its past and current similarities with our own home, Mars, the red planet, is a likely contender in the quest for extra-terrestrial life. In this guest blog post, James Lewis, a PhD student at Imperial College London, takes a brief look at the findings of his recent research. Strap up, we are rocketing over to Mars!

Mars has always been at the forefront of our imaginations when we picture alien life and the discoveries planetary science has made in recent decades reveal that the idea of our neighbouring world having once been inhabited is not so far-fetched. Mars appears to have once been a habitable world, the question is did life ever exist there? This is one of the questions that Curiosity Rover is attempting to shed more light on but results so far have been inconclusive. One potential problem is that the mineralogy of Mars might seriously disrupt experiments looking for evidence of ancient microscopic Martians. Chlorine salts have already been proven to be problematic and in research, published today, and summarised in the following article I have shown that a salt containing iron, sulfur and oxygen, known as jarosite, can also be added to the list of problematic minerals for life detection experiments.

Eberswalde Delta on Mars, evidence for an ancient persistent flow of water over an extended period of time on the Martian surface. Image Credit: NASA/JPL/MSSS.

Eberswalde Delta on Mars, evidence for an ancient persistent flow of water over an extended period of time on the Martian surface. Image Credit: NASA/JPL/MSSS.

The satellites, landers and rovers sent to Mars have started to unravel many of the mysteries of the red planet. Perhaps their most exciting discovery is that ancient Mars may have been a habitable environment for life. The Martian surface at present is extremely cold, exceptionally dry and bombarded by ultraviolet radiation. The atmosphere is at such a low pressure that liquid water would instantly vaporise. However, characteristic landforms and the presence of minerals that we know only form in water have revealed that ancient Mars had persistent surface or near surface liquid water. The presence of liquid water is exciting because it is a precursor for life and for it to persist on the surface would require a warmer thicker atmosphere.

This potentially habitable liquid water existed billions of years ago, so how can we investigate if life ever existed in these environments? If ancient Martians existed they would likely be microscopic organisms like bacteria on Earth. We could look for the fossils they might leave behind but these features would be extremely small and there are many non-biological processes that can form similar structures. The least ambiguous evidence would be to find chemical compounds that only life leaves behind. As biological molecules contain carbon they fall under a chemical class called organic compounds. However, not all organic compounds are biological. For example, asteroids and comets contain non biological organic compounds that formed in the early Solar System.

Comets and asteroids have been impacting Mars throughout its history so when we send missions to Mars we would expect to see the organic molecules delivered by impacts from outer space. The strange thing is that we haven’t. If we can’t detect compounds we know should be there, what are our chances of detecting possible organic compounds indicative of life? All that has been detected so far are very simple organic compounds with chlorine attached. Their origin is uncertain as similar compounds are used as cleaning agents on Earth and sometimes as reagents inside the rovers, so they could just be contamination. However, recent discoveries have complicated things even further; in 2008 a mineral called perchlorate was discovered on Mars. Perchlorate is very rare on Earth as it is only stable in very arid environments such as the Atacama Desert and the Dry Valleys of Antarctica. Perchlorate has now been discovered by multiple Mars’ missions so it would appear it is widespread in the extremely arid present day Martian surface.

The Phoenix Lander made the first detection of perchlorate on Mars in 2008. Dusty Martian soil can be seen in the background and on the Lander’s frame. Image Credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University.

The Phoenix Lander made the first detection of perchlorate on Mars in 2008. Dusty Martian soil can be seen in the background and on the Lander’s frame. Image Credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University.

Perchlorate is a big complication in our search for organic compounds on Mars. The most common technique used to analyse samples for the presence of organic compounds is to heat materials in an inert atmosphere until organic compounds break down and go into the gas phase. The chemical composition of this gas can then be analysed. For example, on the Curiosity rover the gas passes from the sample oven into a and then a mass spectrometer, which separates out the constituent gases and identifies them. The problem with perchlorate is that it breaks down at low temperatures, in fact just at the temperatures that organic molecules would start to break down and be detectable. Perchlorate releases oxygen and chlorine when it thermally decomposes. Oxygen will react with, and break down, organic compounds into carbon dioxide and water. So it will greatly reduce the instrument’s ability to detect organic molecules if it is present in the sample heating oven. The simultaneous release of chlorine by perchlorate could also chemically alter the products of heating experiments. This may explain why so far we have only detected simple chlorinated organic molecules on Mars.

Like previous missions to Mars, Curiosity is detecting only simple organic compounds with chlorine attached. Image Credit: NASA/JPL-Caltech/MSSS

Like previous missions to Mars, Curiosity is detecting only simple organic compounds with chlorine attached. Image Credit: NASA/JPL-Caltech/MSSS

I wanted to investigate the question as to whether perchlorate is the only mineral that might have a negative influence on our search for organic compounds on Mars. I analysed a group of minerals called sulfates. They contain sulfur and oxygen in the form SO4 and include common minerals such as gypsum. When sulfates thermally break down they release sulfur dioxide and oxygen, so they have the potential to be problematic like perchlorate. However, most break down at very high temperatures (above 1000 °C), which is sufficiently high not to interfere with the release of organic molecules from samples during heating experiments. However, iron sulfates start to break down at dramatically lower temperatures. They can decompose to give off sulfur dioxide and oxygen from around 500 °C. This is around the same temperatures that large complex organic molecules might start to break down and be detectable. I was particularly interested in an iron sulfate called jarosite, as it has been detected on Mars, including recent detections by Curiosity Rover, and forms in wet acidic conditions. It’s therefore indicative of ancient wet environments that existed on Mars and may have once been inhabited by microorganisms, as similar environments on present day Earth, such as Río Tinto in Spain are a habitat for acid resistant bacteria.

I conducted fieldwork on a small island in the south of the United Kingdom called Brownsea Island. If you walk along the southern coast of Brownsea you will often see crusts of a soft yellow mineral on the short cliffs. This is jarosite, it grows here because the clay rich rocks that make up the cliff face contain the iron and sulfur mineral pyrite, pyrite reacts with water and the atmosphere to form jarosite. The geology here is a perfect case study as the rocks also contain a tough form of organic matter called lignite, a low rank of coal. I crushed the sample into a powder so that I had a mix of jarosite, clay and organic compounds. I then heated this powder at different temperatures to see if I would be able to detect the organic compounds contained in the sample. Unfortunately all I could detect was carbon dioxide, carbon monoxide, water and sulfur dioxide. The first three are compounds that you would expect to detect if organic matter was breaking down and reacting with oxygen and the sulfur dioxide indicated that the jarosite was thermally decomposing. When a sulfate breaks down we know that sulfur dioxide is paired with oxygen but when I heated this sample the oxygen wasn’t detectable. It had been consumed by reacting with organic compounds and breaking them down. From these results jarosite can now be added to the list of problematic minerals on Mars, alongside perchlorate.

Jarosite is a soft yellow mineral and can be seen growing on the clay rich cliffs of Brownsea Island, UK. As it is an iron mineral it can rust if exposed at the surface long enough in wet conditions. The orange-brown layer at the base of the cliff and the dark patches in the hand sample are rust. Image Credit: James Lewis.

Jarosite is a soft yellow mineral and can be seen growing on the clay rich cliffs of Brownsea Island, UK. As it is an iron mineral it can rust if exposed at the surface long enough in wet conditions. The orange-brown layer at the base of the cliff and the dark patches in the hand sample are rust. Image Credit: James Lewis.

Jarosite is indicative of environments that may have been habitable for life so simply avoiding it is not a satisfactory solution. Though it has a major negative influence on organic detection experiments some interpretation may still be possible. If sulfur dioxide and carbon dioxide peak at the same time in Curiosity Rover data, from a sample known to contain jarosite, it may be evidence that organic matter was present and reacting with oxygen. Unfortunately it is not always the case that a carbon dioxide peak means the presence of organic matter. Minerals known as carbonates contain carbon and oxygen in the form CO3. When carbonates thermally decompose they produce carbon dioxide. Therefore the chance of a carbonate being the source of carbon dioxide seen in Curiosity Rover data must be considered. Fortunately Curiosity has the ability to perform an assessment of the mineralogy it is adding to its heating ovens for analysis, so the presence of carbonates can be checked.

Identifying which rock units on Mars might contain abundant organic compounds would be of great use to future missions that might return samples to the Earth where a whole suite of laboratory techniques can be employed on samples without the tight space and energy constraints of a rover or lander.

My research is published online today in the journal of Astrobiology and will be free for all to read once the open access application is processed.

By James Lewis,  PhD Researcher at Imperial College London

References

Atreya, S.K., Mahaffy, P.R., and Wong, A.: Methane and related trace species on Mars: Origin, loss, implications for life, and habitability, Planetary and Space Science, 55, 358-369, doi:10.1016/j.pss.2006.02.005, 2007.

Glavin, D.P., Freissinet, C., Miller, K.E., et al.: Evidence for perchlorates and the origin of chlorinated hydrocarbons detected by SAM at the Rocknest aeolian deposit in Gale Crater, Journal of Geophysical Research, Planets Vol. 118, 1955-1973, doi:10.1002/jgre.20144, 2013.

Mahaffy, P.: Exploration of the Habitability of Mars: Development of Analytical Protocols for Measurement of Organic Carbon on the 2009 Mars Science Laboratory, Space Sci. Rev 135, 255-268, doi:10.1007/978-0-387-77516-6_18, 2008.

Ming, D.W., Archer, P.D., Glavin, D.P., et al.: Volatile and Organic Compositions of Sedimentary Rocks in Yellowknife Bay, Gale Crater, Mars. Science, 343, 1245267, doi:10.1126/science.1245267, 2013.

 

 

Geosciences Column: Using tall trees to tot up tropical carbon

Forests in the tropics account for about half the above-ground carbon on Earth and as the trees grow older they are capable of storing more and more. In fact, their carbon-storing potential is so large that they are increasingly being viewed as a means of mitigating climate change. Take, for example, the United Nations effort to reduce degradation and deforestation by assigning value to forest carbon.  But programmes like this can only operate if we can calculate forest carbon stocks effectively.

The first step is to suss out a tree’s dimensions. Biomass directly relates to tree height and trunk diameter, so if you know these two details you can work out the amount of carbon stored in a particular tree. This calculation owes its ease to a lot of hard-collected data on tree dimensions and biomass, which, when combined, produces a neat relationship between the two.

Tropical forest in Martinique. (Credit: Wikimedia Commons user Fameme)

Tropical forest in Martinique. Credit: Wikimedia Commons user Fameme)

You can calculate tree height using a tape measure or using LIDAR. LIDAR, short for Light Detection and Ranging, uses a laser to measure the distance to an object by analysing the amount of light reflected back to a detector. Whether you’re using the high tech method or the tape, you’ll always need a little trigonometry. With a quick calculation you can use the distance to the tree base, the distance to the tree top, and the angle from where you’re standing to the top of the tree to work out its height. There are other ways to work this out if you fancy conducting a garden experiment with your smartphone .

But what if you wanted to work out the biomass of not one tree, ten or a hundred, but an entire forest of them? Trekking your way through the trees to measure each in turn would take an unimaginably long time, not to mention that, by the time you finish, the trees you started with will have grown, changed and increased their biomass to boot.

Is there a more practical method? Yes! Satellites are also capable of using LIDAR to estimate tree height remotely – data can be used to calculate the amount of carbon contained in a tropical forest.

Forest canopy in Peru. (Credit: Geoff Gallice)

Forest canopy in Peru. (Credit: Geoff Gallice)

The method is a treat for the budding biogeoscientist. Here’s how it works:

  1. Head out to your favoured forest and use your field skills to measure the height and diameter of 100 or so trees. This means you can ground-truth your measurements and apply them to the rest of the forest.
  2. Scoop up some satellite data on tree height.
  3. Use the relationship between height and biomass that you gathered from trees in the field to find the biomass of the rest of the forest.

A group of scientists, led by Maria Hunter, set out to understand the uncertainty in these measures of biomass. Provided you have your 100 or so local trees as a reference, the biggest uncertainty lies in determining their height. A whole host of uncertainties enter here: from the method used to grab the data to the obstacles that cause you to both over- (in the case of tape measures) or under- (in the case of LIDAR) estimate the height of a tree. Some of these uncertainties can cause major problems for tree height estimation, particularly when the tree is unusually tall.

Despite these difficulties, Hunter found that values for forest biomass were still rather good. This is because many measurement errors cancel each other out when applying the results to a large area.  What’s more, since the majority of trees are not unusually tall, their contribution to biomass determining difficulties are relatively small, leading to an overall error in biomass estimates of approximately 6%. Not too bad at all.

By Sara Mynott, EGU Communications Officer

Reference

Hunter, M. O., Keller, M., Victoria, D., and Morton, D. C.: Tree height and tropical forest biomass estimation, Biogeosciences, 10, 2013.