Will We Run Out of Resources David Denkenberger

Will We Run Out of Resources? David Denkenberger Ph. D. Candidate, Building Systems Program Civil, Environmental, and Architectural Engr, CU Please take a note sheet and evaluation form

Introduction • Economic includes time, aesthetics, taste etc. • Conservation sacrifices these intangibles “freezing in the dark” • Energy efficiency doesn’t sacrifice intangibles “win, win: ” environment, money, and intangibles • Environment is that which primarily affects people, e. g. air and water pollution • Nature is biodiversity and habitat protection • Europe destroyed almost all its nature, but is doing well environmentally (far lower air and water pollution than 100 years ago)1 • Million: mn; billion: bn; trillion: tn

Sustainability • Many people say that the earth simply cannot support 10 billion people at the US standard of living • Won’t work with our current system, but will be forced to change eventually anyway • Ecological footprint is the amount of land that is required to sustainably provide for our energy, minerals, living space, food, fiber, and water (~2. 2 acres of usable land person is our quota)1

Energy • US person primary energy use is ~10 k. W 1 • If start with renewable electricity, need less primary energy, 4 -8 k. W, so say 6 k. W • So 10 bn people require 60 tn watts (TW) • Current wind technology could provide 72 TW 2 • Solar max on land ~6, 000 TW, but practical ~600 TW 3 • If 10% efficient and 200 W/sq m, 3 ~0. 1 acre/person: 5% of ecological footprint quota, but could be in desert or on rooftops • Intermittency: vehicle batteries, building thermal, compressed air, or hydrogen (H 2)

Minerals The mineral we spend the most on is… Cement (limestone)1 Non-energy resources cost 1% of GDP 1 Most money is spent on abundant, e. g. iron and aluminum ~10 x in general rock as copper ore 2 • Copper is not abundant, but worst case scenario is 0. 5% GDP loss if we have to mine general rock because recycle and substitute 1 (or even mine our landfills, like we are doing in some places 3) • May have to start recycling phosphorus (fertilizer) this century 4 (general rock P concentration 10 x copper) • •

Minerals for Energy • Wind turbines, heat pumps, and electric resistance: conventional materials • Nuclear: uranium from ocean 1 • Thin film solar cells: amorphous silicon (not cadmium or indium) • Batteries: lithium tough 2, but nickel, lead, zinc and iron 3 • H 2 electrolysis can be graphite or nickel 4 • Fuel cells: platinum: looking for substitutes; but can just burn H 2 • Combining H 2 with CO 2 from air to make gasoline substitute: done industrially, cheap catalysts 5

Living Space • Typical half acre suburban plot with 3 people is 0. 17 acres/person, or ~8% of ecological footprint quota • Buildings ~0. 5% of footprint (residential 1000 sq ft times 1. 5 to include commercial) • Parking ~0. 6% of footprint 1 • Landfills ~0. 0001% of footprint!2 • Mining ~1% of footprint (based on Natural Capitalism material moved and assumed mine depth and coal reference)

Water • If water is withdrawn and not consumed (evaporated), it is available downstream (and water pollution levels are falling) • Agriculture is 70% of withdrawals, but 93% of consumption 1 • Including rain-fed, agriculture and silviculture (wood) are 99% of consumption 1 • I get lawns ~5% of US consumption, but non-plants (non-land) ~0. 5% (industry, drinking, showers) • Irrigation has reduced our direct ecological footprint ~10%1 and only 1/10 of irrigation is unsustainable, 2 so we will only lose 1% • Humans consume about ¼ of evapotranspiration 1

Fiber • • • By mass of wood, not value (for plantations): Lumber ~5% of footprint quota 1 Paper and cardboard ~5% of footprint 1 Burning (industrial and personal) ~10% of footprint 1 Cotton is ~1% of footprint 2

Food/ Totals • ~70% of footprint with US productivity 1 (if European productivity (similar to US in 1960, but now double US), only ~35%2); land loss, but CO 2 up • Total footprint of American is ~70% of quota, which is sustainable, but more natural forests would be converted to plantations and farming • If problem and needed >100%, price would increase: not build out of or burn wood, use farm residues for paper, waste less food, and eat less meat; all happening in drier countries: cut footprint in half (or future tech like algae flue) • The problem is saving nature, not people

Orders of magnitude of eco footprint quota • 300% food biomass all energy • 100% cellulosic biomass all energy, 10 ac lot (telecommuting), food + fiber if organic and 350 ppm • 30% food, fiber • 10% living space • 3% solar for all energy • 1% mining, roads • 0. 3% wind for all energy, buildings, parking • 0. 1% nuclear for all energy • … • 0. 0001% landfills