Re framing the Re-framing the climat ate change debate Dr Sarah - PowerPoint PPT Presentation

Re framing the Re-framing the climat ate change debate Dr Sarah Mande The Tyndall Cen tre for Climate Change Research The University of Mancheste Climate change a Cli t h and energy: a marine perspective d i ti January 2010

outline 4) UK responses to the challenge e Talk o 1) Dangerous climate change g 3) Global GHG pathways 2) Cumulative emissions g )

What is dange rous climate change? e this as 2 ° C UK & EU define UK & EU define e this as 2 C B t But: … 2 C impacts at the worst end 2°C impacts at the worst end d of the range d of the range … ocean acidification devastati ing even at 400-450ppmv CO 2 g pp 2 … failure to mitigate leaves 2°C C stabilisation highly unlikely

Emission-red duction targets � UK, EU & Global - long � UK EU & Global long g term reduction targets g term reduction targets UK’s 80% r reduction in CO 2 e by 2050 EU 60%-80% EU 60% 80% “ “ 2050 2050 Bali 50% “ 2050 � CO 2 stays in atmosphe ere for 100+ years, � Long-term targets are g g dangerously misleading g y g

ng dangerous climate change (2 ° C) 2050 reduction unrelated to avoidin g g g ( ) cumulative emissions that matter l ti i i th t tt (i (i.e. carbon budget) b b d t) this fundamentally rewrites the time eline of climate change - from long te from long te erm gradual reductions erm gradual reductions - to urgent & radical reductions

How do global te emperatures link to global and natio l b l d ti nal carbon budgets l b b d t & from there to & from there to emission-reduct ion pathways ?

Temperature Temperature threshold science/modelling GHG concentration science/modelling Global cumulative Global emission emission budget emission budget pathway pathway 2000-2008 emissions Apportionment regime pp g + + short-term National emission projections National cumulative pathway h emission budget

… looking at it graphically

pathway for r a CO 2 e budget sions emiss CO 2 e e nual C available carbo on Ann budget budget 2000 2020 2040 2060 2080 2100

pathway for r a CO 2 e budget sions emiss CO 2 e e Plot recent Plot recent t emissions t emissions nual C available carbo on Ann budget budget 2000 2020 2040 2060 2080 2100

2100 2080 r a CO 2 e budget 2060 on available carbo pathway for 2040 budget budget 2020 leased ady rel ns alre Emissio E 2000 CO 2 e e sions emiss nual C Ann

pathway for r a CO 2 e budget sions emiss leased CO 2 e e We can proje We can proje ect: ect: ady rel - Short-te term emissions to peak year/s nual C We know: We know: ns alre - Cumula ative emissions for 2°C available carbo on Ann budget budget Emissio E 2000 2020 2040 2060 2080 2100

pathway for r a CO 2 e budget sions emiss leased CO 2 e e Hence can Hence can n draw emission pathways n draw emission pathways ady rel nual C ns alre available carbo on Ann budget budget Emissio E 2000 2020 2040 2060 2080 2100

2100 2080 r a CO 2 e budget 2060 ange carbon budget ra pathway for 2040 2020 leased ady rel ns alre Emissio E 2000 CO 2 e e sions emiss nual C Ann

Ty Ty yndall’s yndall s emissio on scenarios (2000 0-2100 CO 2 e) To consider: 1. CO 2 emissions fro om landuse ( deforestion ) 2 Non CO GHGs (p 2. Non-CO 2 GHGs (p (principally agriculture ) (principally agriculture ) What emission space remain ns for: 3. CO 2 emissions fro om energy?

Ty Ty yndall’s yndall s emissio on scenarios (2000 0-2100 CO 2 e) � Included very optimistic: y - CO 2 from land-use & forestry emission scenarios

Ty Ty yndall’s yndall s emissio on scenarios (2000 0-2100 CO 2 e) � Included very optimistic: - CO 2 from land-use & forestry emission scenarios

- CO 2 from land-use & forestry emission scenarios 7 6 CO 2 ) Characterised by high O 2 (MtC 5 5 uncertainty (principally driven by deforestation; 12-25% of 4 4 s of CO global CO 2 e) 3 Two Tyndall scenarios with Two Tyndall scenarios with issions different carbon-stock levels 2 remaining: 70% & 80% i i 70% & 80% Em 1 0 2000 2000 0 0 2020 2020 2040 2040 2060 2060 2080 2080 21 21 Year

Ty Ty yndall’s yndall s emissio on scenarios (2000 0-2100 CO 2 e) � Included very optimistic: - land-use & forestry em mission scenarios - non-CO 2 greenhouse CO h gas emissions i i

Ty Ty yndall’s yndall s emissio on scenarios (2000 0-2100 CO 2 e) � Included very optimistic: - land-use & forestry em mission scenarios - non-CO 2 greenhouse CO h gas emissions i i

- non-CO 2 greenho 2 g ouse gas emissions g 14 e) GtCO 2 12 2 ghg (G 10 Marked tail from food related emissions related emissions on-CO 2 8 6 6 s of no Food emissions/capita assumed to halve by 2050 4 4 missions Early action Mid action 2 Late action Late action Em 0 2000 0 2020 2040 2060 2080 21 Year

Ty Ty yndall s yndall’s emissio on scenarios (2000 0-2100 CO 2 e) � Included very optimistic: - land-use & forestry em mission scenarios - non-CO 2 greenhouse CO h gas emissions? i i ? � Global CO e emissions peak � Global CO 2 e emissions peak ks of 2015/20/25? ks of 2015/20/25?

facto oring in… the latest em missions data what is the sca ale of the global g ‘problem’ w we now face?

It’s gettin ng worse! Global CO 2 em mission trends? ~ 2.7% p.a. last 100yrs ~ 3.3% p.a. 2000-2006

latest global CO 2 e g e emission trends? 2 ~ 2.4% p.a. since 2000 ~ Stern assumed 0.95% p p.a. (global peak by 2 2015)

Wh at does: � this failure to reduce e emissions & � the latest science on n cumulative emissions Say about Say about a 2°C future? a 2 C future?

What greenhou se gas emission pathway ys for 2°C

Assumpt tions � 2015/20/25 global peak in em missions � Highly optimistic deforestatio on & food emission reduction � 2°C global carbon budget � 2°C global carbon budget 1400 to 2200 G GtCO 2 e for 2000-2100 � ~ 10% to 60% chance of exc eeding 2°C

Total greenhouse g Total greenhouse g gas emission pathways gas emission pathways 2015 peak 2020 0 peak 2025 peak ses (GtCO 2 e) 80 es (GtCO 2 e) es (GtCO 2 e) 80 80 Low D L Low D H 60 60 60 enhouse gase enhouse gase eenhouse gas Medium D L Medium D Medium D H High D L 40 40 High D H 40 missions of gre issions of gree issions of gre 20 20 20 Em Emi Emi 0 0 0 2000 2020 2040 2060 2080 2100 2000 2020 2040 2060 2080 2 2000 2020 20 40 2060 2080 2100 Year Year Year (Anderson & Bows. 2008 Philosophical Transac ctions A of the Royal Society. 366. pp.3863-3882)

10% - 60% chanc ce of exceeding 2°C g & with a 2 2020 peak 4 5 0 p p m v c u m u la tiv e e m is s io n s c e n a rio s p e a k in g in 2 0 2 0 ) 2 e) 8 0 GtCO Unprecedented L o w A gases (G L o w B L o w B reductions d ti M e d iu m A 6 0 (~ 10% pa M e d iu m B H ig h A from 2020) from 2020) nhouse H ig h B 4 0 of green 2 0 missions Em 0 2 0 0 0 2 0 2 0 2 0 4 4 0 2 0 6 0 2 0 8 0 2 1 0 0 Y e a r Y e a r (Anderson & Bows. 2008 Philosophical Transactions A of the Royal Society. 366. pp.3863-3882)

… and for ene rgy emissions? (with 20 020 peak) 60 2015 peak M edium DL p L 2015 peak High DL 2015 peak High DH 2020 peak High DL 50 2 ) e (GtCO 2020 peak High DH 40 O 2 alone Even then total 30 ons of C decarbonisation by 20 ~ 2035-45 necessary 2035 45 necessary Emissio 10 0 2000 2020 2040 2060 2080 21 Year

What annual global emission reductions from energy f from energy f for 3°C and 4°C for 3 C and 4 C Assume � 2020 global peak in emissio ons � Highly optimistic deforestati � Highly optimistic deforestati tion & food emission reductions tion & food emission reductions � ~ 50% (?) chance of excee eding 3°C & 4°C

For 3°C & emissions For 3 C & emissions peaking by 2020: peaking by 2020: … 9% annual red ductions in CO 2 from energy gy 2 For 4°C & emissions peaking by 2020: p g y … 3.5% annual re eductions in CO 2 from energy

What are the What are the precedents for precedents for such re ductions? Annual reductions of gre ater than 1% p.a. have only “been associated with econo omic recession or upheaval” Stern 2006 � UK gas & French 40x nuclear � UK gas & French 40x nuclear r ~1% p a reductions r ~1% p.a. reductions (ex. aviation & shipping) � Collapse Soviet Union econom � Collapse Soviet Union econom my ~5% p a reductions my 5% p.a. reductions

450p ppmv greenhouse gas e emission pathways (50% chance of f exceeding 2°C)

For a 450ppmv pp v CO 2 future, , 2 … the UK can emit ~ 4 the UK can emit ~ 4 4 8 billion tonnes of carbon 4.8 billion tonnes of carbon between 2000- 2050 Note: this is based on how the U UK Government apportioned global emissions to the UK in order to ca alculate the ‘60% by 2050’ target

From this two q From this two questions arise... questions arise...