The global hectare (gha) is a measurement unit for the ecological footprint of people or activities and the biocapacity of the Earth or its regions. One global hectare is the world's annual amount of biological production for human use and human waste assimilation, per hectare of biologically productive land and fisheries.
It measures production and consumption of different products. It starts with the total biological production and waste assimilation in the world, including crops, forests (both wood production and CO2 absorption), grazing and fishing.[1] The total of these kinds of production, weighted by the richness of the land they use,[1] is divided by the number of hectares used. Biologically productive areas include cropland, forest and fishing grounds, and do not include deserts, glaciers and the open ocean.[2]
"Global hectares per person" refers to the amount of production and waste assimilation per person on the planet. In 2012 there were approximately 12.2 billion global hectares of production and waste assimilation, averaging 1.7 global hectares per person.[3] Consumption totaled 20.1 billion global hectares or 2.8 global hectares per person, meaning about 65% more was consumed than produced. This is possible because there are natural reserves all around the globe that function as backup food, material and energy supplies, although only for a relatively short period of time. Due to rapid population growth, these reserves are being depleted at an ever increasing tempo (see Earth Overshoot Day).
The term "global hectare" was introduced in the early 2000s,[4] based on a similar concept from the 1970s named "ghost acreage".[5] Opponents and defenders of the concept have discussed its strengths and weaknesses.[6]
YouTube Encyclopedic
-
1/2Views:41 75544 027
-
Earth Overshoot Day 2015 is on Aug. 13th
-
Human Population Impacts
Transcription
Hi Alex here. Have you heard of ecological footprint and earth overshoot day? Our ecological footprint is how much we demand from nature currently humanity is using the equivalent of one point six planets every year global footprint network calculates earth overshoot day it marks the date when humanity is demanding on nature exceeds what the earth can regenerate in that year. In 2000 earth overshoot day fell in early October. And in 2015 he falls on August 13th. You can think about this as a bank account for the first seven months and 13 days in 2015 we lived on our annual revenue, after that we spent our capital Hmmm, seems like there's something wrong with that math our ecological footprint measures how much land and water area we need to produce the resources we use things like food, lands for settlements, timber, seafood and to absorb the waste and carbon dioxide which generate our biocapacity is the amount of biologically productive areas such as forests, fishing grounds, crop and grazing areas that are available to provide the resources we use and to absorb or waste. We can compare footprint and biocapacity to see if we are well balanced or not so why do we care about humanity's ecological footprint? the cost of ecological overspending are evident every day in the form of deforestation, drought, biodiversity loss, and the build up of carbon dioxide in the atmosphere. Ecological overspending also can put nations at more risk without sufficient resources it is hard to operate an economy or we have to import more which has costs as well. Carbon emissions from fossil fuel use are a big part of today's footprint Today, humanity's carbon footprint makes up 54 percent of the world's total ecological footprint. If we continue business as usual we would need the resources equivalent to two planets by 2030. Earth overshoot day would be moved up on the calendar to the end of June in 2030 However, there is another option. The global agreement being discussed worldwide to phase out fossil fuels could help reduce the world's ecological footprint. If global carbon emissions alone are reduced by at least 30 percent below today's level by 2030 earth overshoot day would be moved back on the calendar to mid-september such large cuts are not impossible Denmark has done it. Since the nineteen nineties Denmark reduced its carbon emissions by one third had the world done the same thing why not changing the rest the footprint earth overshoot day would be on October 3rd instead of August 13th in 2015. This would also limit global warming to 2 degrees Celsius over pre-industrial revolution levels the target suggested by climate scientists and a big step in the right direction I am sure hoping that the United Nations climate talks in Paris at the end of this year will help us do just that. We mostly talked about footprints for nations but you can also measure the ecological footprint of an individual a city or a business. I calculated my ecological footprint on Global Footprint Network's website and it is around 3.9 global hectares. I live in Canada, which has a footprint of 7 global hectares per person why is mine smaller? Well mostly thanks to my life style I try to not eat very much meat, I drive little, and I live in a highly energy efficient house The ecological footprint helps me understand our relationship to the planet so if you want to give us a hand you can start by calculating your own footprint on footprintcalculator.org This video was created in collaboration with Global Footprint Network an international think tank that coordinates research, develops methodological standards and provides decision-makers with a menu of tools to help the human economy operate within earth's ecological limits. If you enjoyed this video, please subscribe and share it with your friends and colleagues. Our free sustainability videos are financed with an honour system if you think, like us, that it is important work you can contribute the amount of your choice by clicking on the orange button and as usual thank you for watching.
Applications
The global hectare is a useful measure of biocapacity as it can convert things like human dietary requirements into common units, which can show how many people a certain region on earth can sustain, assuming current technologies and agricultural methods. It can be used as a way of determining the relative carrying capacity of the earth.
Different hectares of land can provide different amounts of global hectares. For example, a hectare of lush area with high rainfall would scale higher in global hectares than would a hectare of desert.
It can also be used to show that consuming different foods may increase the earth's ability to support larger populations. To illustrate, producing meat generally requires more land and energy than what producing vegetables requires; sustaining a meat-based diet would require a less populated planet.
Hectare equivalents
On average, a global hectare can be produced in the area of a standard hectare. A hectare (/ˈhɛktɛər/; symbol ha) is a unit of area equal to 10,000 square metres (107,639 sq ft) (a square 100 metres on each side or 328 feet on each side), 2.471 acres, 0.01 square kilometers, 0.00386102 square miles, or one square hectometre (100 metres squared).
See also
References
- ^ a b Borucke, Michael; Moore, David; Cranston, Gemma; Gracey, Kyle; Iha, Katsunori; Larson, Joy; Lazarus, Elias; Morales, Juan Carlos; Wackernagel, Mathis (2013). "Accounting for demand and supply of the biosphere's regenerative capacity: The National Footprint Accounts' underlying methodology and framework". The Living Planet Report 2016 cites this paper to explain the "conversion from actual land areas to global hectares.". Ecological Indicators. 24: 518–533. doi:10.1016/j.ecolind.2012.08.005.
- ^ "FAQs: What is a global hectare?". Global Footprint Network. Retrieved 8 May 2012.
- ^ WWF (2016). Living Planet Report 2016. Gland, Switzerland: WWF International. p. 77. ISBN 978-2-940529-40-7.
- ^ Proceedings of the National Academy of Sciences of the United States of America vol. 99 (2002), p. 9266.
- ^ Mathis Wackernagel, William Rees, Our Ecological Footprint: Reducing Human Impact on the Earth (1998), p. 49.
- ^ Galli, Alessandro; Giampietro, Mario; Goldfinger, Steve; Lazarus, Elias; Lin, David; Saltelli, Andrea; Wackernagel, Mathis; Müller, Felix (2016). "Questioning the Ecological Footprint" (PDF). Ecological Indicators. 69: 224–232. doi:10.1016/j.ecolind.2016.04.014.
This page was last edited on 19 March 2024, at 14:55