lecture 4 enviro impact on biofuels

Question 1

renewable energy obligations and directives

Answer 1

• In the UK, the Renewable Transport Fuel Obligation (RTFO) imposes an obligation on fuel suppliers to supply 5% of road fuels from renewable sources
  • The 2009 Renewable Energy Directive sets a target for the UK to achieve 15% of its energy consumption from renewable sources by 2020. This compares to 3% in 2009.
  • In 2011, mandatory sustainability criteria was introduced

Question 2

consequences of demand and concerns about bioenergy crops

Answer 2

This increase in demand has resulted in a massive expansion in the area of bioenergy crops – greater land use
• Concerns have been expressed that growing bioenergy crops is neither energy or carbon efficient and may have adverse environmental impacts

Question 3

direct environmental impacts

Answer 3

• land use change (including deforestation)
• greenhouse gas emissions
• eutrophication
• acidification
• pesticide toxicity
• water quantity and quality
• loss of soil and soil quality
• loss of biodiversity and genetic diversity

Question 4

Indirect Environmental Impacts

Answer 4

• Increased fertilizer manufacture leads to greater energy demand (the production of nitrogen fertilizer already uses 1.5% of global energy)
  • Increased pesticide manufacture leads to increasing levels of toxic pollutants in soil and water with a detrimental on biodiversity
  • Land use change results in increased emissions of greenhouse gas which results in global warming

Question 5

other impacts

Answer 5

• Competition for land resulting in food security issues and food prices increasing
• Distortion of global markets through policy pollution
• Loss of livelihood and cultural identity

Question 6

What percentage of global carbon dioxide emissions is due to deforestation

Answer 6

Deforestation is responsible for between 6 and 17% of global carbon dioxide emissions

Question 7

Malaysia and Indonesia are increasing production of palm oil and biodiesel to supply the European market

(Land use change)

Answer 7

• In Southeast Asia, palm oil expansion is one of the leading causes of rainforest destruction
• Two-thirds of palm oil production in Indonesia is based on conversion (destruction) of rainforests
• In 1997/98, 10 Mha of rainforest were cleared for biofuel production; this doubled annual global CO2 emissions
• Land use change may lead to increased emissions of GHGs and a loss of biodiversity
• Biofuel production and hence an increase in the area of biofuel crops is driven by policy

Oil Palm Plantation

Question 8

carbon neutrality in biofuels, true or false

Answer 8

Biofuels are often promoted to be carbon neutral
• This is partially true since the carbon sequestrated during plant growth is released during combustion of the fuel
• However, additional energy is required in the production of biofuels which emits carbon dioxide: • manufacture of fertilizers and pesticides uses electricity and natural gas • agricultural production requires diesel and electricity • processing and refining needs electricity and natural gas • logistical stages rely on diesel
• Biofuels are not carbon neutral … but some are better than others

Question 9

eutrophication potential

Answer 9

High levels of phosphates and nitrates in surface waters promotes excessive algae growth which when they die and decompose causes hypoxia
• Normally expressed as phosphate equivalents

Question 10

acidification

Answer 10

Potential of acids, having been submitted to the atmosphere, to cause acidification of soils and water
• Causes forest dieback, fish death and reduces biodiversity
• Measures in terms of sulphur dioxide equivalents

Question 11

water use fro biofuel crops

Answer 11

Biofuels crops, like food crops, require water for growth
• Water demand changes with crop location and type
• The production of biofuels increases demands on this already pressurised resource

Question 12

loss of biodiversity

Answer 12

• usually a monoculture (as crops usually are)
  • Loss of biodiversity invariably follows
  • The change from food crops to biofuel crops in mature cropland has little or no affect on biodiversity
  • Establishing plantation crops in place of natural forest has very large negative affects

Question 13

land use

Answer 13

• Biofuel crops compete for land with food crops
• Maize and wheat can be used for bioethanol production instead of flour production
• In 2009 food riots broke out in Mexico and the Philippines in response to rising food prices
• If all UK arable land grew oilseed rape for biodiesel, it would still not meet demand

Question 14

food

Answer 14

• demand for food will increase by 70% by 2050 - eliminating efficiencies within the supply chain will meet some of that demand but production will have to increase:
• agricultural area
• increase population per area