State of the Climate 2018: Bureau of Meteorology and CSIRO

State of the Climate 2018: Bureau of Meteorology and CSIROState of the Climate 2018 is the latest biennial snapshot of climate change in Australia. It focuses on observed long-term trends that are happening now and are likely to continue into the near future, as well as significant climate events that have occurred over the past two years. These changes are described through the latest observations from CSIRO and Bureau of Meteorology marine, atmospheric and terrestrial monitoring programs.

The report also summarises the latest climate research from Australia and around the world. This will help inform a range of economic, environmental and social risk assessments and responses by government, industry and communities.

Multiple lines of evidence show the climate system changing in ways that are discernible from natural variability, and consistent with a human influence on climate. These changes are having an impact on our natural and built environment.

In particular, climate change is being felt through an increase in the frequency and severity of high-impact weather events such as heatwaves, extreme fire weather conditions, coastal inundation and marine heatwaves. These trends are projected to continue.

Some of the report’s major findings are described below.

Passing major milestones

Australia’s average air temperature has warmed by just over 1℃ since national records began in 1910. Oceans around Australia have also warmed by around 1℃ since 1910.

State of the Climate 2018: Bureau of Meteorology and CSIRO Annual mean temperature over Australia and the seas surrounding Australia. Bureau of Meteorology, Author provided

Atmospheric concentrations of carbon dioxide are rising globally. Emissions from the burning of fossil fuels continue to increase, and are the main contributor to the rise in CO₂, with some contribution from changes in land use.

Atmospheric CO₂ concentrations measured at Cape Grim, Tasmania (one of three main global measuring stations, alongside Mauna Loa, Hawaii, and Nunavut, Canada), have persisted at levels above 400 parts per million (ppm) since 2016. What’s more, the combined concentration of all greenhouse gases exceeded the equivalent of 500 ppm CO₂ in mid-2018. These milestones haven’t been crossed for at least 800,000 years, and likely 2 million years.

Changes in the atmosphere and land

Australia’s warming trend has led to an increase in the frequency of extreme heat events. For example, very high monthly maximum temperatures that used to occur around 2% of the time (based on the average for 1951–80) now happen about 12% of the time (2003–17).

Other elements of Australia’s climate have also shown long-term changes. New analysis techniques now provide a more detailed picture of changes to fire weather through time. The annual total of daily values of the Forest Fire Danger Index is increasing over large areas of Australia. Most regions also saw an increase in the most extreme 10% of fire weather days, and fire seasons have lengthened.

Rainfall in April–October has been steadily decreasing in Western Australia’s Southwest, and has decreased since the 1990s in southeast Australia. In contrast, rainfall has increased in parts of northern Australia since the 1970s.

The observed long-term reduction in rainfall across southern Australia has led to even greater reductions in streamflow. Long-term average streamflow has decreased in most regions of southern Australia, and increased in regions of northern Australia.

A warmer atmosphere can hold more moisture, and this is an important driver of the observed increase in the intensity of short-duration rainfall, sometimes linked to flash flooding. Southern Australia is projected to experience decreases in average rainfall and more time spent in drought. Meanwhile, most of the country can expect an increase in rainfall intensity.

Historically, significant weather and climate events are often the result of the combined influence of several extreme factors at once. Higher temperatures during periods of below-average rainfall, for instance, can exacerbate drought conditions. Temperature, dryness and wind come together to create dangerous bushfire conditions.

State of the Climate 2018: Bureau of Meteorology and CSIRO Trend in the annual sum of Forest Fire Danger Index, 1978–2017. Bureau of Meteorology, Author provided

Changes in the ocean

The warming in Australia’s oceans has contributed to longer and more frequent marine heatwaves – defined as periods when sea surface temperatures are much warmer than average. The world’s oceans are a crucial moderator of the climate, taking up more than 90% of the extra heat in the system – most of it is absorbed by the Southern Ocean.

Sea levels continue to rise through the combined effects of warming oceans and melting ice from land-based glaciers and ice sheets. Global average sea level has risen by more than 20cm since 1880, but the rate varies from place to place. About 25% of the CO₂ emitted by human activity diffuses into the oceans, making them more acidic in the process.

The past two years, 2016 and 2017, have seen back-to-back bleaching events in parts of the Great Barrier Reef, linked to marine heatwave events. These changes are very likely linked to warming oceans, and primarily driven by the human influence on the climate.

State of the Climate 2018: Bureau of Meteorology and CSIRO Global sea level change from 1880 estimated from tide gauges and satellites. CSIRO, Author provided

Well-established scientific theory and climate model studies both show that the warming would largely not have occurred without the increase in greenhouse gas concentrations. In addition, the current increase in temperatures accords with projections made nearly 30 years ago. Warming is projected to continue into the future as the effect of past emissions continue, and more greenhouse gases are emitted. Australia is projected to experience increases in sea and air temperatures, with more hot days and marine heatwaves, and fewer cool extremes.

It takes time for the climate system to warm in response to increases in greenhouse gases, and the historical emissions over the past century have locked in some warming over the next two decades, regardless of any changes we might make to global emissions in that period. However, by the mid-21st century, higher ongoing emissions of greenhouse gases will lead to greater warming and associated impacts, and reducing emissions will lead to less warming and fewer associated impacts.

State of the Climate 2018: Bureau of Meteorology and CSIRO Australian average annual temperature 1861-1900 period in observations and global climate models. CSIRO, Author provided

You can also watch accompanying behind-the-scenes videos on our research on climate extremes and ocean warming.The Conversation

About The Author

Michael Grose, Climate Projections Scientist, CSIRO and Lynette Bettio, , Australian Bureau of Meteorology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Related Books

InnerSelf Market

Amazon

follow InnerSelf on

facebook icontwitter iconyoutube iconinstagram iconpintrest iconrss icon

 Get The Latest By Email

Weekly Magazine Daily Inspiration

EVIDENCE

smoke stacks 5 12
Climate Change First Went Viral Exactly 70 Years Ago
by Marc Hudson, University of Sussex
We have grown so used to many things. To the pictures of wildfires and cremated animals, to the ice sheets calving into…
will you reconize 5 8
The Dangers of Crossing Tipping Points
by InnerSelf Staff
The planet is currently facing a grave threat due to climate change. Global warming is causing environmental changes…
Record Low Antarctic Sea Ice Is Another Alarming Sign
by Craig Stevens, National Institute of Water and Atmospheric Research
A changing climate is upon us, with more frequent land and marine heatwaves, forest fires, atmospheric rivers and…
Here’s Why Ocean Temperatures Are The Hottest On Record
by Moninya Roughan, UNSW Sydney
Large swathes of the world’s oceans are warm. Unusually warm. The heat this year is likely to break records. Since…
Blue water surrounded by dead white grass
Map tracks 30 years of extreme snowmelt across US
by Mikayla Mace-Arizona
A new map of extreme snowmelt events over the last 30 years clarifies the processes that drive rapid melting.
White sea ice in blue water with the sun setting reflected in the water
Earth’s frozen areas are shrinking 33K square miles a year
by Texas A&M University
The Earth’s cryosphere is shrinking by 33,000 square miles (87,000 square kilometers) per year.
wind turbines
A controversial US book is feeding climate denial in Australia. Its central claim is true, yet irrelevant
by Ian Lowe, Emeritus Professor, School of Science, Griffith University
My heart sank last week to see conservative Australian commentator Alan Jones championing a contentious book about…
image
Reuters' Hot List of climate scientists is geographically skewed: why this matters
by Nina Hunter, Post-Doctoral Researcher, University of KwaZulu-Natal
The Reuters Hot List of “the world’s top climate scientists” is causing a buzz in the climate change community. Reuters…

LATEST VIDEOS

The Great Climate Migration Has Begun
The Great Climate Migration Has Begun
by Super User
The climate crisis is forcing thousands around the world to flee as their homes become increasingly uninhabitable.
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
by Alan N Williams, et al
The latest report from the Intergovernmental Panel on Climate Change (IPCC) states that without a substantial decrease…
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
by Toby Tyrrell
It took evolution 3 or 4 billion years to produce Homo sapiens. If the climate had completely failed just once in that…
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
by Brice Rea
The end of the last ice age, around 12,000 years ago, was characterised by a final cold phase called the Younger Dryas.…
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
by Frank Wesselingh and Matteo Lattuada
Imagine you are on the coast, looking out to sea. In front of you lies 100 metres of barren sand that looks like a…
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
by Richard Ernst
We can learn a lot about climate change from Venus, our sister planet. Venus currently has a surface temperature of…
Five Climate Disbeliefs: A Crash Course In Climate Misinformation
The Five Climate Disbeliefs: A Crash Course In Climate Misinformation
by John Cook
This video is a crash course in climate misinformation, summarizing the key arguments used to cast doubt on the reality…
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
by Julie Brigham-Grette and Steve Petsch
Every year, sea ice cover in the Arctic Ocean shrinks to a low point in mid-September. This year it measures just 1.44…

LATEST ARTICLES

How Wildfire Smoke Can Harm Human Health, Even When The Fire Is Hundreds Of Miles Away – A Toxicologist Explains
by Christopher T. Migliaccio
Smoke from more than 100 wildfires burning across Canada has been turning skies hazy in North American cities far from…
Atlantic Hurricane Season 2023: El Niño And Extreme Atlantic Ocean Heat Are About To Clash
by Christina Patricola
The Atlantic hurricane season starts on June 1, and forecasters are keeping a close eye on rising ocean temperatures,…
How Climate Change Is Impacting The Hudson Bay Lowlands — Canada’s Largest Wetland
by Matt Morison, University of Winnipeg and Nora Casson, University of Winnipeg
The starkly beautiful Hudson Bay Lowlands, located between the Canadian Shield and Hudson Bay, are covered in…
How Corporations Use Greenwashing To Convince You They Are Battling Climate Change
by Tom Lyon, University of Michigan
Many corporations claim their products are “green-friendly.” But how do you know if what they’re selling is truly…
smoke stacks 5 12
Climate Change First Went Viral Exactly 70 Years Ago
by Marc Hudson, University of Sussex
We have grown so used to many things. To the pictures of wildfires and cremated animals, to the ice sheets calving into…
Fire Danger In The High Mountains Is Intensifying
by Mohammad Reza Alizadeh, Massachusetts Institute of Technology (MIT) and Mojtaba Sadegh, Boise State University
As wildfire risk rises in the West, wildland firefighters and officials are keeping a closer eye on the high mountains…
Historic Flooding In Fort Lauderdale Was A Sign Of Things To Come
by Smitha Rao, The Ohio State University
When a powerful storm flooded neighborhoods in Fort Lauderdale, Florida, in April with what preliminary reports show…
What Is Hydrogen, And Can It Really Become A Climate Solution?
by Hannes van der Watt, University of North Dakota
Hydrogen, or H₂, is getting a lot of attention lately as governments in the U.S., Canada and Europe push to cut their…

 Get The Latest By Email

Weekly Magazine Daily Inspiration

New Attitudes - New Possibilities

InnerSelf.comClimateImpactNews.com | InnerPower.net
MightyNatural.com | WholisticPolitics.com | InnerSelf Market
Copyright ©1985 - 2021 InnerSelf Publications. All Rights Reserved.