dealing with climate variability and climate change · 2018-09-06 · climate variability and...

Dealing with Climate Variability and Climate Change

Bernadette Sloyan (CSIRO), Alex Sen Gupta (UNSW), and Matthew England (UNSW)


Pacific and Indian Tropical Oceans Angus Santos (UNSW)

Polar and mid-latitude oceans Andy Hogg (ANU)

Australian coastal and shelf oceans Peter Oke (CSIRO)

Paleoclimate Katrin Meissner (UNSW)

Ocean biogeochemical cycles Bronte Tilbrook (CSIRO)

Sea level and ocean heat and freshwater content

John Church (CSIRO)

Marine Extremes Kathleen McInnes (CSIRO) and Ron Cox (UNSW)

Seven key areas were identified that underpin understanding of this Theme as identified in the Marine Nation 2025 document. With input from over 100 Australian Climate Scientists

Climate Variability and Climate Change: ImpactsGlobal Mean Sea Level increased by 210mm between 1880 and 2009, and is continuing to rise at a fairly steady rate of just over 3mm/year. This rate of rise is undoubtedly contributing to the flooding problems of low-lying island states like Tuvalu, Kiribati and the Maldives.

This is exacerbated in some areas (e.g. Gippsland, Victoria ) where large-scale land subsidence causes a rate of rise relative to the land which is substantially higher.

Climate Variability and Climate Change: Impacts

Recent estimates by the Climate Council are that almost 250,000 homes around Australia worth about $72 billion are vulnerable to a 1.1 metre rise in sea levels. Key infrastructure -road, rail, ports, airports, water and wastewater services, energy and communications- public assets and commercial assets swell the national sum that is at risk to about $226 billion.


Vulnerabilities due to multiple stresses

Sea-level riseWarmingAcidificationHypoxiaStratificationStorm Surges

source: IPCC WGII 2014


Australia’s aquaculture and fisheries industry, worth about $2.23B and tourism industry (Great Barrier Reef generates $6B) both of which rely on a healthy, productive marine environments.

G. Degradation of coral reefs and associated fish stocksH. Temperature-

driven shifts in stock of large pelagic fish

9. Mass Coral bleaching, decline in growth rate and loss of marine biodiversity

8. Ocean acidification reduces biological calcification and alters plankton communities

D. Higher sea level modifiescoastlines with increase risk

of flooding and impact marine aquaculture industries

Climate Variability and Climate Change: Impacts The Great Barrier Reef has experienced bleaching events in 1980, 1982, 1992, 1994, 1998, 2002, and 2006. Widespread and intense events occurred in the summers of 1998 and 2002, with 42% and 54% respectively of reefs bleached to some extent, and 18% strongly bleached.

The Great Barrier Reef is also under pressure from tropical cyclones, ocean acidification, invasive marine species and declining water quality.


0 20 40 60 80 1000

20

40

60

80

100

120

140

160

180

200

% of years

% o

f lo

ng-t

erm

incom

e

no forecast

forecast

Benefit of using coupled ocean-atmosphere models for agribusiness management decisions


N fertilizer (kg N/ha)

Pro

fit

($/h

a)

Risk (# loss years; mean loss)

Forecast

Current farmers practice

VV

Historical

knowledge

Coupled

forecast

Benefit of

forecast

$94 /ha $161 /ha$67 /ha

= 71%

Use of coupled forecast (with dynamic ocean) improves realisable farm yield and profits

An example for WA wheat region

Climate Variability and Climate Change

Illustration of the seven spheres of the Earth System, which are intertwined and physically coupled through exchange fluxes of energy,momentum, and matter, and biogeochemicallycoupled through fluxes of carbon and other substances.


The Ocean regions surrounding Australia are important in the earths climate for the key climate variables:•heat, •water, •carbon and•nutrients.


The ocean surrounding Australia have experience significant trends over the recent period

Temperature Trends

Freshwater Trends


Using rainfall anomalies as a proxy for extreme El Nino, occurrences of extreme El Nino-like event are projected to double


• under UV light inshore GBR corals show luminescent lines

• due to humic acids from soils during flood events

• proxy for river flow and rainfall


• 1974 wettest year

• dry period late 18th-early 19th

century

•extremes becoming more extreme

• extremes occurring more often

Tripled length of instrumental record

Lough, 2011


Variability is due to modest warming trend and a systematic transition to boundary currents thermocline that are significantly less stable.

The shift to warm boundary currents coincides with a weakening of the Hadley cell and a 40% reduction in the strength of the subtropical jet.

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Figure 1. Vertical cross-section of July zonal wind (m s-1), averaged over 100º-130ºE longitude, as a function of latitude and

pressure (hPa) for the 1949-1968 basic state, and for the difference (1975-1994) - (1949-1968). Plots (a) and (d) for

NCEP/NCAR data as in FF05. Plots (b) and (e) for the ATM simulation (control) and (c) and (f) for the 20CRV2 data.

Contour intervals are 10 m s-1 for the 1949-1968 basic state and 2 m s-1 for the difference (1975-1994) - (1949-1968)

with stippling indicating the 95% significance level from Student's t-test. Negative (positive) values are indicated by dashed

(solid) lines.


High-latitude oceans (modulated by seasonally-varying sea-ice coverage) help to govern the ocean’s overturning circulation to control oceanic heat and carbon storage on long timescales


Fort DenisonFremantle

The effect of sea level rise during the 20th century at two Australian sites.

The Average Recurrence Interval for extremes sea level was reduced by a factor of around three at both sites, so that an extreme that used to occur, say, every three years now occurs every one year.


A schematic of the ocean observing system


Australia is a significant partner in all of the components of the ocean observing system – both in maintaining the observing system and providing scientific oversight.

We strongly leverage our limited resources to further international invest in our region.


Australian researcher also need to participate in intensive process studies.

The Southwest Pacific Ocean Circulation and Climate Experiment (SPICE)

T-TideUSACanadaAustralia


IOCCPGOA-ON

SOCATSOOS

GO-SHIPFOO

GCP


GO-SHIP/GLODAP

IOCCP/SOCAT

Air-sea CO2 Flux

anthropogenic CO2 storage

Climate Variability and Climate ChangeObservational synthesis products (e.g. SOCAT) of air-sea CO2 exchange is used to determine the global carbon budget. The atmosphere and ocean accumulation of CO2 allows the land sink to be resolved. This work is feeding into yearly updates of the global carbon budget (www.globalcarbonproject.org).

Climate Variability and Climate ChangeBLUElink is an ocean modelling and analysis tool used for accurately forecasting ocean conditions.

BLUElink Reanalysis (BRAN), provides a time-varying picture of the ocean circulation over the past 20 years.

Climate Variability and Climate ChangeBLUElink is an ocean modelling and analysis tool used for accurately forecasting ocean conditions.

The global ocean model that underpins BLUElink is called the Ocean Forecasting Australia Model (OFAM)

The operational system is called OceanMAPS – the Ocean Modelling Analysis and Prediction System. This produces

daily, 7-day forecasts of ocean conditions.


The Australian Community Climate Earth System Simulator (ACCESS) is our national climate model. ACCESS is a numerical model of the major elements of the climate system that affect the Earth’s weather and climate. It provides global and national climate change assessments.

12km Atmosphere, 10km oceanClimate Variability and Climate Change

Tropical Cyclone Yasi Sea surface velocities from control (a) and ensemble ocean –atmosphere prediction system(b).

(Sandery and O’Kane 2013)

Coupled ocean-atmospheric prediction system

Climate Variability and Climate ChangeAustralian Climate research is highly qualified and respected in the international climate community


Marine science priorities for “dealing with climate variability and change.”

•Enhanced understanding of ocean-cryosphere-atmosphere-biogeochemical variability and controls on interocean exchanges by wind, heat and freshwater fluxes.

•Improved knowledge of the impact of increasing greenhouse gas concentrations on the complex interplay between major climate phenomena and ocean-cryosphere-atmosphere-biogeochemical dynamics

•Increased understanding of the mechanisms and impacts of multi-decadal variability and longer-term trends on Australian and regional climate (including Asia and Pacific Islands).

Challenges

• High quality observations and adequate Research Vessel access

• Global and regional ocean climate modelling of world-class standard with a Southern Hemisphere focus

• Computational & storage resources meeting the next decade’s scientific needs

• Adequate and sustained research funding targeting the marine climate sector



Investment in Australian and regional marine climate variability and change research provides significant benefit to a diverse group of end-users including national, state and local governments, national defence organisations, tourism, fisheries and aquaculture, off-shore oil and gas and renewable energy industries, marine parks and regulatory authorities.

The research undertaken by this science community underpins development of climate products and services needed by industry, the public and policy makers.


Bernadette Sloyan (CSIRO), Alex Sen Gupta (UNSW), and Matthew England (UNSW)

dealing with climate variability and climate change · 2018-09-06 · climate variability and...

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