Energy and the Environment

3 categories of environmental impacts

air, land, water

How coal power plants interact with the environment

flue gases, cooling water, electricity

How nuclear power plants interact with the environment

cooling water, electricity

Oil Spills

Deepwater Horizon

Hurricane Ike aftermath

caused half-million gallons of crude oil to spill

Old Oil Sullies Waller Creek

fuel oil that had been sitting idle in an underground storage tank for 100+ years got umped out by a water leak

Frequency of oil spills

decreased over time

Water quality risks from energy production

• thermal pollution from power plants

• runoff from biofuels production

• spills of frac fluids for shale production

• contamination from mines for coal, uranium, and other critical minerals

Deaths due to air pollution

7 million deaths from all sources of air pollution

Solid particles from power plant emissions

• Large: soot, fly ash, metallic particles, dust (falls near where emitted)

• Heavy Metals: such as Mercury (Hg)

• Particulate Matter: solids or liquid aerosols with diameter less than 500 um, can travel long distances, easily inhaled

Gases from power plant emissions

CO, CO2, NOx, SOx

CO2 from power plants

• from combustion of carbon/hydrocarbons

• products are CO2 and H2O

SOx emissiosn

• coal contains 102% sulfure

• becomes SO2 after combustion (13 Ibs/MWh)

• SOx and H2O creates sulfuric acid (acid rain)

• SOx and NH3 creates ammonium sulfate (PM)

• both a pollutant (bad) and lubricity agent (good)

NOx emissions

• produced from high-temperature combustion

• coal produces more NOx than natural gas

• NOx is poisonous by itself

• NOx and VOCs create ozone and photochemical smog

• NOx and H2O creates nitric acid (acid rain)

• NOx and NH3 creates ammonium nitrate (PM)

Large Particle scrubbing technology

use electrostatic precipitators (99% effective)

CO scrubbing technology

lean combustion

SOx scrubbing technology

flue gas desulfurization (FGD), limestone scrubbers

NOx scrubbing technology

ammonia injection

Car emissions

• major concern is smog (NOx, HCs)

• particulate matter/soot

• CO2 emissions

• Texas has program to get cash to turn in older/dirtier cars

Clean Air Act (1963)

• first federal law to address air pollution

• amendment required to set NAAQS for 6 criteria pollutants (CO, Pb, NO2, O3, PM, SO2)

Trend of aggregate emissions

has been going down

Rank of carbon emissiosn by fuel

coal > petroleum > natural gas

Waste disposal

• mining tails (coal, uranium, rare earth metals)

• solid waste from coal

• solid waste from nuclear

Renewables source with most minerals used

offshore wind

Solid waste from coal

• fly ash contains a significant amounts of pollutants (carcinogens, heavy metals, arsenic)\

• toxic substances that would have been spewed into the air have been shifted to solid byproducts

• production of post-combustion waste has increased sharply

• second-largest waste stream in the country, after municipal solid waste

Nuclear Waste

• from nuclear reactors

• 91,000 metric tons of spent nuclear fuel sit onsite

• waste is stored in either cooling pools or dry casks

Solar and wind end-of-life

• 25-30 year lifespan

• sometimes contain hazardous/toxic materials

• sometimes difficult to recycle due to composite materials

• trying to recycle reusable materials instead of going to landfills

• most wind turbine materials can be recycled

Wind turbine affects on wildlife

• kill birds and bats

• california wind farms will shut down for 2 months during migratory seasons

• highest bird deaths due to feral cats

Surface Mining and Control Act

• once mining is complete

• overburden and top soil is returned

• contoured to original topography

• restores with native grasses and shrubs

Decarbonization of environmental impacts

• manure (from horses) to slag and fly ash (from coal) to fission products (from uranium)

Entropy and the environment

• reducing the entropy of environmental impacts requires less work for mitigation

• pollution with higher disorder has higher entropy (air pollution to water pollution to solid pollution)

• avoiding waste is more energyefficient than cleaning it up after the fact

Net-Zero/Carbon Neutral

• GHGs still produced but are either captured before emitted or directly removed from the atmosphere

• no change in atmospheric GHG level occurs

Zero Emissions

No GHGs are emitted

Carbon Capture and Sequestration (CCS)

• at power plant, CO2 is separated from flue gas using liquid solvents, solid sorbents, or semi-permeable membranes

• CO2 is injected into geological formations

Bioenergy with CCS (BECCS)

• biomass absorbs CO2 from atmosphere using energy from the sun

• when biomass is used in power plant with CCS, more carbon is absorbed than emitted

Direct Air Capture (DAC)

• removes CO2 directly from atmosphere

• primarily use solid sorbents or aqueous solutions to remove CO2 from the air

Temperature of Venus

• higher than all other planets

• atmosphere is 96.5% CO2

Climate

• general weather over the medium term

• usually over a 30-year period

• temperature, rainfall, wind speed, storm frequency

Consensus around climate science

• CO2 traps heat

• CO2 levels have increased steadily since the second industrial revolution (1850)

• source of new CO2 is primarily fossil fuel combustion

• global temperatures and sea levels have risen

• many people will suffer if temperatures and sea levels continue to rise

Potential losers of climate change

• biggest hardships might fall on the poor areas of the world

• flooding of coastal areas

• increased dryness at low latitudes (Southwest US, equatorial countries)

Potential winners of climate change

Canada and Russia might benefit with increased growing season and production of crops

Primary forcing function of climate change

• greenhouse gases

• have higher radiative forcing than the baseline atmosphere

• traps more heat in the atmosphere

• raises global average temperature

3 main factors for GHG impacts on climate change

• how much of the gas is in the atmosphere

• how long it persists in the atmosphere

• how strongly it impacts global temperatures

CO2-Equivalent

normalize for the global warming potential

Global Warming Potential

The ratio of the time-inegrated radiative forcing from the instantaneous release of 1 kilogram or a trace substance relative to that of 1 kg of a reference gas (CO2)

Cooling forcing effect

aerosols and albedo

Atmosphere concentration growth

• emissions minus sinks

• as emissions of CO2 are increasing, the capacity of sinks are decreasing, atmospherec CO2 icnrease as a result

The Carbon Cycle

• large reservoirs and relatively small fluxes

• flows include the preindustrial and anthropogenic ocean-atmosphere and land-atmosphere exchanges

Airborne fraction of CO2

• stays constant with time

• only 40% remain in the atmosphere, rest is absorbed by the oceans and the land biota to about equal proportions

Percent of GHGs from CO2

79%

Most common source of CO2 emissions

from fossil fuel combustion (transportation)

Proof CO2 is from fossil fuels

• compare levels to pre-industrial revolution

• atmosphereic levels of carbon in the air have changed in accordance with what we would expect from combustion of old plants (C12 instead of C13)

Main source of CH4 emissions

natural gas and agriculture

Main source of N2O emissions

agriculture

Largest CO2 emitting country

China

Primarily cumulative contributor of GHGs

U.S.

The UN Intergovernmental Panel on Climate Change (IPCC)

• informs energy policy

• UNited Nations body for assessing teh science related to climate change

• Issue assessment reports on climate change science, impacts, adaptation, and mitigation

• more than 75% of global greenhouse gas emissions are due to the energy sector

The ‘Hockey Stick’ Curve

shsows recent rapid increase in temperature

Sea Level Rise

• caused by melting ice sheets and thermal expansion of sea water

• sea level rose 4-8 inches in the 20th century

• melting polar cap doesn’t increase sea level

• groundwater pumping and runoff

Ocean Warming

• about 90% of global warming is occuring in the ocean

• expanding water is responsible for up to half of global sea level rise

• coral bleaching

• changes in ocean health and biochemistry

Unkowns of climate change

• effect of feedback loops is unkown

• regional impacts are unkown

• effects of take up of CO2 by oceans

• total amount of sea level rise

• concsensus-science downplays uncertainty

Future climate change

• expected to increase the severity of impacts

• risk of species loss

• risk to human health from heat and humidity

• food production impacts

• fisheries yield impacts

• extreme weather events

• displacement/migration

Mitigation Strategy

• reduce emissions

• cap-and-trade

• carbon taxes

Adaption Strategy

• get ready for a new world

• build levees and flood barriers

• build more resilient infrastrucure

• move to minnesota

U.S. climate policy in Trump administration

• openly dismisses climate science

• supports coal, oil and gas

• supports nuclear, geothermal, hydro

Different sources of resistance to action on climate change

• popular resistance

• industrial resistance

• religious resistance

• political resistance

Religious viewpoitns on climate change

• Apocalyptic Views: environmental destruction will bring on the apocalypse

• God is sovereign: anthropogenic effects are minimal, “arrogance of man”

• Good environmental stewards: gaining popularity, building coalitions

Ozone hole vs. global climate change

• Ozone: caused by specific gases, few manufacturers, susbtitutes available

• Climate change: caused by many sources, no easy substitute for fossil fuels, many manufacturers/emitters/producers