Resources Research

Culture and systems of knowledge, cultivation and food, population and consumption

Posts Tagged ‘land use change

Human influence on climate system is clear, says IPCC summary

with 2 comments

IPCC_AR5_blue_strip_smallMajor update: On 30 September 2013 the IPCC released the Final Draft Report of the Working Group I contribution to the IPCC Fifth Assessment Report Climate Change 2013. This is commonly called ‘The Physical Science Basis’. It consists of the full scientific and technical assessment undertaken by Working Group I.

The Final Draft consists of 19 documents – 14 chapters, three annexes, a technical summary and a changes summary. These you will find via this list:

01 Technical Summary (6.05 MB)
02 Ch01 Introduction (2.66 MB)
03 Ch02 Observations: Atmosphere and Surface (10.40 MB)
04 Ch03 Observations: Ocean (18.10 MB)
05 Ch04 Observations: Cryosphere (5.18 MB)
06 Ch05 Information from Paleoclimate Archives (4.78 MB)
07 Ch06 Carbon and Other Biogeochemical Cycles (8.90 MB)
08 Ch07 Clouds and Aerosols (3.48 MB)
09 Ch08 Anthropogenic and Natural Radiative Forcing (2.83 MB)
10 Ch09 Evaluation of Climate Models (6.81 MB)
11 Ch10 Detection and Attribution of Climate Change: from Global to Regional (4.39 MB)
12 Ch11 Near-term Climate Change: Projections and Predictability (5.45 MB)
13 Ch12 Long-term Climate Change: Projections, Commitments and Irreversibility (25.50 MB)
14 Ch13 Sea Level Change (6.17 MB)
15 Ch14 Climate Phenomena and their Relevance for Future Regional Climate Change (7.74 MB)
16 Annex I: Atlas of Global and Regional Climate Projections (36.50 MB)
17 Annex II: Glossary (0.80 MB)
18 Annex III: Acronyms and Regional Abbreviations (0.50 MB)
19 Changes to the Underlying Scientific/Technical Assessment (0.20 MB)

Map of the observed surface temperature change from 1901 to 2012 derived from temperature trends. The globally averaged combined land and ocean surface temperature data as calculated by a linear trend, show a warming of 0.85 [0.65 to 1.06] °C, over the period 1880–2012. For the longest period when calculation of regional trends is sufficiently complete (1901–2012), almost the entire globe has experienced surface warming. Source: IPCC

Map of the observed surface temperature change from 1901 to 2012 derived from temperature trends. The globally averaged combined land and ocean surface temperature data as calculated by a linear trend, show a warming of 0.85 [0.65 to 1.06] °C, over the period 1880–2012. For the longest period when calculation of regional trends is sufficiently complete (1901–2012), almost the entire globe has experienced surface warming. Source: IPCC

Early statements and releases from the Twelfth Session of Working Group I which was held from 2013 September 23-26 in Stockholm, Sweden. The press release about the human influence on the climate system is here, which has said “this is evident in most regions of the globe”.

The IPCC has also provided headline statements from the Summary for Policymakers of the Working Group contribution to AR5. At the Session, the Summary for Policymakers (SPM) of the Working Group I contribution to the IPCC Fifth Assessment Report (WGI AR5) was approved and the underlying scientific and technical assessment accepted. (See the earlier post on the AR5 process.)

IPCC_AR5_WG!_strips1For the Fifth Assessment Report, the scientific community has defined a set of four new scenarios. These are called Representative Concentration Pathways (RCPs). These four RCPs include one ‘mitigation scenario’ leading to a very low radiative forcing level (RCP2.6). (Radiative forcing is the change in net irradiance; it is used to assess and compare the anthropogenic and natural drivers of climate change). There are two ‘stabilisation scenarios’ (RCP4.5 and RCP6), and one scenario with very high greenhouse gas emissions (RCP8.5). The RCPs can thus represent a range of 21st century climate policies.

IPCC_AR5_WG!_strips2

The cereals demand footprint of smaller Indian cities

leave a comment »

All those squares need to grow wheat, rice and millets for the residents of this town of 123,286 people.

All those squares need to grow wheat, rice and millets for the residents of this town of 123,286 people.

On this map you can see, near the centre, the town of Amalner, in the state of Maharashtra, in the district of Jalgaon. In 2001 Amalner was a Class II town, as categorised by the Census of India based on its population being under 100,000 people – its population then was 91,490.

In the 2011 Census the population of Amalner was 116,750 which means the town has crossed the 100,000 mark and for the ten years between the two censuses, its population grew at just under 2.8% every year. Although rapid, that still places Amalner comfortably under the 3.4% average annual population growth rate of the 500 towns and cities whose details we have in the 2011 Census.

rg_amalner_section1How much food do the residents of Amalner need every year? Estimating the quantities is relatively less troublesome for cereals, whereas for pulses, vegetables, fruit, dairy and meat it is progressively more difficult and unreliable.

The squares on the map are scaled for the map, and that means each square is 100 hectares large at the scale of the map. They show the land area required to supply Amalner’s residents their wheat, rice and millets mix (I have taken a 40:40:20 mix as typical for Maharashtra). Crop yield data are from the Ministry of Agriculture, Department of Economics and Statistics, averaged, and adjusted for milled quantities of rice and wheat (but not millet).

How much wheat, rice and millet? The unmilled quantities I estimated are, for 2001: 5,940 tons (wheat), 7,630 tons (rice) and 2,670 tons (millets). For 2013 the quantities are: 8,000 tons (wheat), 10,290 tons (rice) and 3,600 tons (millets). The annual cereals requirement is based on the Indian Council of Medical Research (ICMR) 2010 recommended dietary allowance (cereal 400 gm/capita/day).

Now this graphic, plotted on a map that shows the urban extent of Amalner, also shows the land ‘footprint’ of cereals that a typical smaller town requires. We have now much greater interest in urban agriculture than even two years earlier, and while these networks have begun to thrive, this analysis demonstrates the dependence by urban residents on districts to supply them cereals and pulses.

rg_amalner_section2In the graphic, the squares under the caption ‘additional cereals area in 2013’ show the new hectares required to be brought under cereals cultivation to meet the calorie needs and nutritional standards for Amalner’s growing population. The use of these squares on the map serves to show why land use change for urbanisation runs quickly into physical limits – provided those physical limits are recognised and planned for.

There are about 130 such urban settlements with populations of plus-minus 10,000 relative to the population of Amalner. Above this group are the cities with populations of 150,000 and above all the way to the million-plus metropolises. Below this set are the much more numerous small towns with populations of 20,000 to 100,000 and whose demand for food, and therefore on the maintenance of cultivated, is hardly known or measured.

Amalner’s 2.8% population growth rate every year also tells us there are migrants coming into the town. When those additional migrants are also cultivators and former agricultural labour, what will happen to the old and new hectares the cities need to keep cultivated? Where will the food come from?

Exposé of false carbon accounting for biofuels

with 4 comments

Cover of a brochure on a 'biorefinery' project in Sweden

Cover of a brochure on a 'biorefinery' project in Sweden

False carbon accounting for biofuels that ignores emissions in landuse change is a major driver of global natural habitat destruction, incurring carbon debts that take decades and centuries to repay; at the same time, the emissions of nitrous oxide from fertilizer use has been greatly underestimated, says a damning new briefing from the Institute of Science in Society (I-SIS), Britain.

A team of thirteen scientists led by Timothy Searchinger at Princeton University, New Jersey, in the United States, pointed to a “far-reaching” flaw in carbon emissions accounting for biofuels in the Kyoto Protocol and in climate legislation. It leaves out CO2 emission from tailpipes and smokestacks when bioenergy is used, and most seriously of all, it does not count emissions from land use change when biomass is grown and harvested, says the I-SIS briefing.

“The team maintained that bioenergy reduces greenhouse emission only if the growth and harvesting of the biomass for energy captures carbon above and beyond what would be sequestered anyway, and offsets the emissions from energy use. This additional carbon may result from land management changes that increase plant uptake or from the use of biomass that would otherwise decompose rapidly.”

Graph from World Energy Outlook 2010 titled 'Ranges of well-to-wheels emission savings relative to gasoline and diesel'.

Graph from World Energy Outlook 2010 titled 'Ranges of well-to-wheels emission savings relative to gasoline and diesel'.

“The worst case is when the bioenergy crops displace forest or grassland, the carbon released from soils and vegetation, plus lost future sequestration generate huge carbon debts against the carbon the crops absorb, which could take decades and hundreds of years to repay.”

The work of Searchinger, referred to by I-SIS, has been mentioned in connection with this false accounting as long as a year ago. For instance, the Industrial Biotechnology and Climate Change blog had noted in 2009 November:

The Science Insider blog last week hosted an interesting debate between Tim Searchinger, Princeton visiting scholar, and John Sheehan, of the Institute on the Environment at the University of Minnesota, regarding the recent policy proposal in the pages of Science by Searchinger et al. to ‘fix’ the carbon accounting of biomass for bioenergy and biofuels in U.S. legislation and the successor to the Kyoto protocol, by giving credit only to biomass that can be managed in such a way as to sequester additional atmospheric carbon in the soil. As Searchinger puts it in the recent debate, “bioenergy only reduces greenhouse gases if it results from additional plant growth or in some other way uses carbon that would not otherwise be stored.”

Cover of the World Energy Outlook 2010 report, International Energy Agency

Cover of the World Energy Outlook 2010 report, International Energy Agency

Also pertinent is a short section on biofuels and emissions in the World Energy Outlook 2010, which has recently been released by the International Energy Agency. “Biofuels are derived from renewable biomass feedstocks, but biofuels are not emission-free on a life-cycle basis,” says WEO2010. There is keen debate about the level of emissions savings that can be attributed to the use of biofuels and, more generally, to biomass. Greenhouse-gas emissions can occur at any step of the biofuels supply chain. Besides emissions at the combustion stage, greenhouse-gas emissions arise from fossil-energy use in the construction and operation of the biofuels conversion plant. In addition, the cultivation of biomass requires fertilisers, the use of machinery and irrigation, all of which also generate emissions.”

The short section is part of Chapter 12 – titled ‘Outlook for Renewable Energy’ – of the massive tome, and the section on Biofuels emissions is found in pages 372-374. As the WEO must perforce sound upbeat about all forms and sources of energy, it ventures, “If appropriate feedstocks and process conditions are chosen, biofuels can offer significant net greenhouse-gas emissions savings over conventional fossil fuels”. That’s a big “if” there.

“This is particularly the case with sugar cane ethanol, as much less energy is required to convert the biomass to ethanol.” In a laboratory perhaps, but as there are as many ways of converting sugarcane as there are types of cane, it would be difficult to say, wouldn’t it?  “But variations are large and calculating average emissions savings is complex.” So they are, so it is.

After such kerfuffle, the WEO2010 does get down to brass tacks: “Using land for biofuels production that was previously covered with carbon-rich forest or where the soil carbon content is high can release considerable amounts of greenhouse gases, and even lead to a ‘carbon debt’. In the worst cases, this debt could take hundreds or even thousands of years to recover via the savings in emissions by substituting biofuels for fossil fuels.”

And there you have it, in black and white, from the venerable International Energy Agency itself.