Are we ready ? Our changing climate.

Professor Mark HowdenANU Institute for Climate, Energy and Disaster SolutionsVice Chair, IPCC Working Group II @ProfMarkHowden

CO2 emissions: record fall from COVID

Global Carbon Project 2020; Friedlingstein et al. 2020 Year

UPDATE

CO

2fo

ssil

fuel

em

issi

ons

(Gt C

O2/y

ear)

20206.7% decrease

Atmospheric GHGs: still breaking records

NASA 2021, NOAA 2021

• CO2 today 418.7ppm

• Record levels of methane and last year highest growth ever

• Record levels of nitrous oxide

• Record levels of other GHGs

Globally – warming accelerating• Equal warmest

year on record (1.24oC above the pre-industrial average)

• 40% chance of exceeding 1.5oC at least once in next 5 years

• Likely to breach 1.5oC by early 2030s

HADCRUT5; GISTEMP; NOAA; Berkeley Earth; WMO 2021

Glo

bal m

ean

tem

pera

ture

diff

eren

ce fr

om

1850

-190

0 (o

C)

MDB: record temperatures

BoM 2021

BoM 2021

Extremes almost everywhere, all the time

Frost risk increasing in SE Australia

Howden et al. 2004, Crimp et al. 2016

Screen minimum temperature (oC)

Day of last frost (10th percentile)

180

220

300

260

0-2 2

MDB rainfall trends

BoM 2021

• Declines across most of the basin

• Particularly across the high-yielding upper catchments

Change in pressure systems: Australia

BoM 2021

Change in pressure systems: Sthn hemisphere

BoM 2021

Vapour pressure deficit (VPD) increasing

Yuan et al. 2019

MDB flows: historical

MDBA 2020

Climate changes dragging back farm profits

Hughes et al. 2020

• Climate changes (post 2000) affecting farm profits from -37% (Vic.) to +8.7% (NT)

Climate changes drag back global ag productivity

Ortiz-Bobea et al. 2021

• Global average agricultural productivity reduced by 21%

Choices about our future

Global Carbon Project 2018

Current trajectory

Paris Agreement commitments

2oC1.5oC

2020 Estimate

Temperature projections

IPCC 2013

Daytime Night-time

Low emissions

High emissions

Climate reduces total water storage

Pokhrel et al. 2021

In this region too:• Proportionally

more summer rain• Higher rainfall

intensity• Increased season

to season variability

• Increased potential evaporation

MDB flows: historical and projected

MDBA 2020; CSIRO 2021

2030 2050 2080

Drought becomes much worse: global

Pokhrel et al. 2021

• Food prices likely to increase

• Food trade increase due to variability in supply

• Competitive advantage to those who adapt best

Unlikely to achieve the Paris Agreement goals

• On current trends, the probability of staying below 2°C of warming is only 5%

• But if all countries meet their nationally determined contributions and continue to reduce emissions at the same rate after 2030, it rises to 26%

• For a given temperature goal, the time to net zero is not fixed – stronger interim targets push out the net-zero date and vice versa

• Strong rationale for increasing adaptation action• Many opportunities in the regions in emission-reduction

Liu and Raftery 2021

Reconfiguring: your goals and resources• The evidence of climate change and its impacts keeps accumulating and the news is not good

• Future projections look worse the more we know• Rapid and substantial action is needed and is publically supported • We all have roles to play - together

Key messages

Thank you

Prof Mark HowdenANU Institute for Climate, Energy and Disaster Solutionsmark.howden@anu.edu.au@ProfMarkHowden+61 2 6125 7266

Vice Chair, IPCC Working Group II