Category Archives: anthropocene

Warming, not cooling: three recent graphs that conclusively show the planet heating

Warming, not cooling: ocean heat content

One the myths peddled by the denial machine is that there has been a pause in warming. 

Indeed, Britain’s “nuttiest weather forecaster” Piers Corbyn is predicting a mini ice age. Jo Nova looked at the last year years of temperature data and concluded the world might have entered a cooling phase.

Of course, such claims are completely divorced from reality. Two recent studies and Australia’s experience over summer offer conclusive proof the planet is warming, and that we’re living in a changed climate.

No doubt many of you have already seen the study of ocean warming by Balmaseda, Trenberth, and Källén (2013) published in Geophysical Research Letters (DOI: 10.1002/grl.50382)

The elusive nature of the post-2004 upper ocean warming has exposed uncertainties in the ocean’s role in the Earth’s energy budget and transient climate sensitivity. Here we present the time evolution of the global ocean heat content for 1958 through 2009 from a new observational-based reanalysis of the ocean. Volcanic eruptions and El Niño events are identified as sharp cooling events punctuating a long-term ocean warming trend, while heating continues during the recent upper-ocean-warming hiatus, but the heat is absorbed in the deeper ocean. In the last decade, about 30% of the warming has occurred below 700 m, contributing significantly to an acceleration of the warming trend. The warming below 700 m remains even when the Argo observing system is withdrawn although the trends are reduced. Sensitivity experiments illustrate that surface wind variability is largely responsible for the changing ocean heat vertical distribution.

Put simply, global warming has been accelerating: 90% of global warming has been going into the oceans, heating them considerably.

Of course, there is the recent Marcott et.al paper looking at the last 11,500 years of temperature anomalies:

A new hockey stick

While Australia has just experienced the “Angry Summer“:

6883-DCCEE-Summer-Heat-Infographs_SUMMARY_v6_1MARCH-2

The oceans are warming at an alarming rate; temperature records are being smashed not just in Australia, but across the world; the present warming trend is unlike anything we’ve seen in thousands of years.

Of course, the denial machine has gone into overdrive ever more desperate attempts to cast doubt on the science.

Thus we’re left with a stark choice; accept the science, or believe the entire scientific community is lying.

Climate change: is victory at hand?

Author Paul Gilding (who I very much admire) has written an interesting post, claiming that victory is at hand:

There are signs the climate movement could be on the verge of a remarkable and surprising victory. If we read the current context correctly, and if the movement can adjust its strategy to capture the opportunity presented, it could usher in the fastest and most dramatic economic transformation in history. This would include the removal of the oil, coal and gas industries from the economy in just a few decades and their replacement with new industries and, for the most part, entirely new companies. It would be the greatest transfer of wealth and power between industries and countries the world has ever seen.

Gilding suggests that we saw a significant shift in the public debate last year, and that this will lead to a profound shift in both the debate and official responses:

I have come to this conclusion after reflecting on a year when an avalanche of new knowledge and indicators made both tipping points clear. The first and perhaps the best understood is the rapid acceleration in climate impacts, reinforcing the view many hold that the scientific consensus on climate has badly underestimated the timing and scale of climate impacts. The melting of the Arctic Sea Ice, decades before expected, was the poster child of this but extreme weather and temperature records across the world, notably in the USA, suggested this Arctic melting is a symptom of accelerating system change. 

It also became clear that this was literally just the “warm up” act – that we are currently heading for a global temperature increase of 4°C or more, double the agreed target. 

In response came a series of increasingly dire warnings from conservative bodies like the International Energy Agency, the World Bank and the International Monetary Fund. Perhaps most colourfully, the IMF chief and former conservative French finance minister, Christine Lagarde, said that without strong action “future generations will be roasted, toasted, fried and grilled”. The World Bank was similarly blunt about the economic consequences of our current path: “there is also no certainty that adaptation to a 4°C world is possible.”

I’m less sanguine: I agree, last year we saw a shift in the debate with greater numbers of the public accepting the science. However, public acceptance of the science is notoriously fickle.

The real question is how fast our civilisation responds.

Time may be against us.

At this point it is very much a race against tipping points.

Melbourne’s exceptional heatwave and climate change: this ain’t the weather your grandparents knew

St.Kilda Beach in the 1930s: when life was simpler, and the planet cooler

St.Kilda Beach in the 1930s: when life was simpler, and the planet cooler*

Melbourne is famous for its extremes of weather. As the old Crowded House song so beautifully put it, to live in Melbourne is to experience Four Seasons in One Day

We’re accustomed to blistering summers and bone-chilling winters. Less familiar are blistering Autumns.

For those who didn’t know, Melbourne is in the midst of a record-breaking heat-wave that has seen the temperature stay above 30 degrees Celsius for eight days now.

Nor is there any relief in sight; according to the Bureau of Meteorology we can expect at least two more days and nights of extreme heat.

This will surpass the previous record of seven days set in February 1961.

The remarkable fact is that we’re officially in Autumn.

According to the Country Fire Authority (CFA), by Wednesday the entire state will be exposed to some risk of bush or grass fires. Areas marked blue denote areas of high fire danger, those coded yellow pertain to areas of very high fire danger:

CFA update

CFA update for Wednesday 13/3/2013

Without doubt we’re entering a new climate regime:

Future warming of the climate due to greenhouse gas emissions will very likely lead to further increases in the frequency of unusually hot days and nights and continued declines in unusually cold days and nights.

These changes will result in weather events which are increasingly beyond our prior experiences.

The climate denial crowd will try to tell you “It’s just weather!”

Or they’ll claim it was just as hot fifty, seventy or one hundred years ago. 

There may have been some hot days – but this heatwave ain’t nothing our grandparents, or our great-grand parents ever experienced.

The world has warmed during the last 150 years: the present heat wave is a harbinger of future extremes.

Welcome to the Anthropocene.

 

*Source: Museum of Victoria

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Stunner: The hockey stick just got scarier, a new temp reconstruction of the last 11k years

Published today in Science, the paper A Reconstruction of Regional and Global Temperature for the Past 11,300 Years (Marcott et.al) shows the stunning – hell, terrifying – increase in temperatures that has taken place since industrialisation.

Michael Mann’s famous hockey stick graph reconstructed the temperature for the last 2000 years. It not only became iconic, but a target for those wishing to cast doubt on the science.

Marcott et.al. do not merely replicate Mann’s work, but extend the time-frame to cover the previous 11,000 years:

Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ~2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.

To put into perspective, before the founding of the first cities.

Our civilisation has existed in “the sweetest of sweet spots” – a time of relatively stable climatic conditions.

In the last 10,000 years we have seen the emergence of agriculture, the establishment of great cities, the founding of great civilisations and the invention of writing.

None of this would have been possible without a benign and forgiving climate.

What is different about the past century and a half is the speed of those changes: note the spike in temperature anomalies for what is essentially the period of industrialisation (1850 ff). 

The climate has always changed: no self-respecting scientist or climatologist has ever denied this. Temperature records are but one proxy of this change – the multiple lines of evidence for climate change are overwhelming.

Note also the last sentence in that abstract: Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.

To translate: all the models point to a future that is warmer than anything we’ve seen for the last 10,000 years.

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The new climate state: climate change and the deadly extremes that have been hitting the northern hemisphere

cparker_blogclouds2

We live in an ocean of air: however the thin, fragile membrane that envelops our planet is changing from one state to another.

The ever-increasing levels of greenhouse gases are trapping more and more heat.

By changing the chemistry of the atmosphere, we change the climate.

Welcome to the anthropocene.

The following paper with the less than sexy title of Quasiresonant amplification of planetary waves and recent Northern Hemisphere weather extremes is getting quite a bit of attention. An early edition of the paper is now available on the Proceedings of the National Academy of Sciences (PNAS) website (see link).

It is a dense, technical piece. If you have the fortitude or technical ability then I highly recommend it. The research was conducted at the Potsdam Institute for Climate Impact Research in Germany. This is deep science, not the faux science of an 800 word post on Watts up with that?

It describes the mechanism that has been driving the devastating extremes across the northern hemisphere these past few years. In short, climate change is repeatedly disturbing the patterns of airflow around the northern hemisphere.

The abstract:

In recent years, the Northern Hemisphere has suffered several devastating regional summer weather extremes, such as the European heat wave in 2003, the Russian heat wave and the Indus river flood in Pakistan in 2010, and the heat wave in the United States in 2011. Here, we propose a common mechanism for the generation of persistent longitudinal planetary-scale high-amplitude patterns of the atmospheric circulation in the Northern Hemisphere midlatitudes. Those patterns—with zonal wave numbers m = 6, 7, or 8—are characteristic of the above extremes. We show that these patterns might result from trapping within midlatitude waveguides of free synoptic waves with zonal wave numbers k ≈ m. Usually, the quasistationary dynamical response with the above wave numbers m to climatological mean thermal and orographic forcing is weak. Such midlatitude waveguides, however, may favor a strong magnification of that response through quasiresonance.

The even shorter abstract: the recent destructive climate events in the heatwaves in the US and Europe, the flooding in China and Japan in 2012 can be attributed to changed atmospheric conditions.

See also this fantastic video on extreme weather:

Quote: “Weather that forms now, forms in a different state”.

In other words, the attribution debate is over: we’ve loaded the weather dice against ourselves.

Signal from the noise: climate change is having a deadly impact already.

I’m interested in readers thoughts, especially those of you with technical backgrounds in climate on this paper.

Discuss.

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Global warming “paused”? Its the oceans stupid (reprint)

Andrew Glikson of the ANU has a great piece on The Conversations today dealing with the “global warming paused” myth that is endlessly recycled by climate change deniers. Glikson makes a great point: by solely focusing on land temperature data,  faux-sceptics wave away the fact the planet’s oceans are warming and provide some of the strongest evidence for climate change. Some 90% of the heat is trapped in the world’s oceans: figure 3 below provides a stunning illustration of this fact. 

Fact check: has global warming paused? by Andrew Glikson

“The UN’s climate change chief, Rajendra Pachauri, has acknowledged a 17-year pause in global temperature rises, confirmed recently by Britain’s Met Office, but said it would need to last ‘30 to 40 years at least’ to break the long-term global warming trend.” – The Australian, Feb 22 2013

Since the onset of the industrial age (from 1750 AD) Earth’s atmosphere, surface and ocean temperatures have warmed. This is mainly due to the rise in greenhouse gases (CO2, CH4, N2O, O3, halocarbons, stratospheric water vapour from CH4) by a total of +3.06 Watt/m2. Other drivers include black carbon (+0.1 Watt/m2) and solar irradiance – the latter during the first half of the 20th century (+0.12 Watt/m2).

Warming was in part mitigated by emitted sulphur aerosols (direct effects -0.5 Watt/m2; cloud albedo effects -0.7 Watt/m2) and by land clearing (-0.2 Watt/m2).

Cyclic, regional and transient climate effects are related to the ENSO cycle, water vapour (whose concentration depends on air temperature) and volcanic events. The fastest warming occurs in the polar regions: this is where there is the biggest albedo (or reflectiveness) contrast between ice and water, and where little or no water vapour exists in the atmosphere.

The consequent warming trend, as measured by NASA, NOAA and Hadley-Met and analysed by Berkeley (see Figure 1), indicates a rise in average land temperature by about +1.5°C over the past 250 years, and about +0.9°C in the past 50 years. A sharp rise in temperatures from about 1975-1976 was related to both an accelerated rise in CO2 and a decrease in emission of SO2 from coal and oil due to clean air policies (see Figure 2). Cleaner air decreases the reflectiveness of the atmosphere, thus driving further warming.

Figure 1: Mean continent-ocean global warming since 1750 http://berkeleyearth.org/results-summary/

Following a sharp El Niño peak in 1998, since about 2000 a slowing down of the mean rate of global warming was related to a sharp increase in SO2 emission from coal mainly in China (see Figure 2), strong La Niña events and a low in the 11 years sun-spot cycle.

Figure 2: Anthropogenic sulphur dioxide emissions 1850-2005. http://www.atmos-chem-phys.net/11/1101/2011/acp-11-1101-2011.pdf

As some 90% of the global heat rise is trapped in the oceans (since 1950, more than 20×1022 joules), the ocean heat level reflects global warming more accurately than land and atmosphere warming. The heat content of the ocean has risen since about 2000 by about 4×1022 joules.

Figure 3: Build-up in Earth’s total heat content. http://www.skepticalscience.com/docs/Comment_on_DK12.pdf

The rise in land and atmosphere temperatures since about 1996 reflects a combination of greenhouse radiative forcing from 360 to 395ppm CO2 at rates of up to 2.54ppm/year (unprecedented since 55 million years ago), the ENSO cycle and 11-years sunspot cycle. Peak temperatures at around 2006 exceed any measured in the instrumental record.

Figure 4: NASA Land-ocean temperatures http://data.giss.nasa.gov/gistemp/graphs_v3/

To summarise, claims that warming has paused over the last 16 years (1997-2012) take no account of ocean heating.

At the root of the issue is the non-acceptance by some of the reality of the greenhouse effect, known since the 19th century and consistent with the basic laws of greenhouse gas radiative forcing and black body radiation.

Andrew Glikson does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.The Conversation

This article was originally published at The Conversation.
Read the original article.

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The new normal: Fires come close to Melbourne, fire plume visable from city

Source: The Age

Source: The Age

This is extraordinary:

AT LEAST one home was destroyed and frightened residents and workers fled as a fast-moving fire came close to Melbourne’s outer northern suburbs. 

The grassfire became an out of control blaze, burning more than 2000 hectares as it headed south from Donnybrook towards urban Epping and Campbellfield. 

More than 600 firefighters in 120 trucks came from across Victoria to battle the flames on a hot and gusty day. They were supported by 11 waterbombing aircraft.

You can see the smoke from the city centre, this time-lapse video shows the fire plume:

 

 

 

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Snow? Climate change and blizzards – yes, there is a connection

For those who think extreme snow fall and precipitation events somehow disprove climate change, I’d direct them to the following graph

Looking like a trend…

According to the National Oceanic and Atmospheric Administration (NOAA):

Rising ocean surface temperatures already have increased the temperature and moisture content of the air passing over the United States, setting the stage for heavier snow and rain storms. Global warming has increased the risk of dumping heavier precipitation — as rain or snow — over most land regions that experience storms.

In the U.S., the region that has experienced the highest increase in heaviest precipitation is the Northeast over the last half century. According to NOAA, the Northeast saw a 74 percent increase in the amount of precipitation that fell during the heaviest rain and snow events between 1958 and 2011.

Yes, you read correctly: a 74% increase in the “the amount of precipitation that fell during the heaviest rain and snow events between 1958 and 2011.”

The science isn’t really that hard to understand: increased moisture in the atmosphere and changes to the climate will lead to an increased number of extreme – if not record-breaking – precipitation events.

Or in English, blizzards and rainfall that comes with an increased frequency and intensity.

Think of a kettle on the stove: as the water begins to boil, steam pours from the spout. Now what if the kettle is sitting inside a hutch or locked cabinet? The steam will hit the roof, condense and fall back down.

Now translate these well understood physics to the climate system: as temperatures rise over time, more moisture content is present in the air. It has nowhere else to go, except down…

And when it comes down on major cities or heavily populated areas it causes black outs, transport chaos and devastation.

Or – we could pretend it is not happening.

Just like climate change denier US Sen. Jim Inhofe we could force our grandchildren to build an igloo in order to mock the claims of climate scientists:

Climate change denial prompts it’s own form of child labour

Who’s laughing now?

[Hat tip Dianne S for this]

Increases in rainfall extremes linked to global warming (reprint)

2011-queensland-floods-the-big-wet

The flooding in Queensland and New South Wales was a devastating and record breaking. Despite claims that increased rainfall somehow disproves the reality of climate change, such extremes are to be expected in a warming world. Seth Westra of the University of Adelaide has a good article on the topic which I’ve republished below. Note, it originally appeared on The Conversation. – Mike @ WtD

Increases in rainfall extremes linked to global warming

Seth Westra, University of Adelaide

Rainfall extremes are increasing around the world, and the increase is linked to the warming of the atmosphere which has taken place since pre-industrial times. This is the conclusion of a recent study which investigated extreme rainfall trends using data from 8326 weather-recording stations globally, some of which have records spanning more than a hundred years.

Of all the stations analysed, we found that two-thirds showed increasing trends over the course of the 20th and early 21st centuries. When we looked at the association between the intensity of rainfall extremes and a record of global mean near-surface atmospheric temperature, rainfall intensity was found to increase at a rate of between 5.9% and 7.7% for each degree, depending on the method of analysis.

This kind of change is precisely what can be expected if one assumes that the intensity of the most extreme rainfall events will scale with the capacity of the atmosphere to hold moisture. This is well known to increase with temperature at a rate of about 7% per degree.

Looking beyond globally averaged numbers, however, we also found distinct regional differences. The greatest increases occurred in the tropical belt; the smallest in the drier mid-latitudes where you will find most of the world’s deserts. In the higher latitudes, particularly in the northern hemisphere, the rate of change was close to the global average. Again, such changes seemed to be in quite close agreement with what global climate models say should happen as a result of global warming: a reassuring case of observations confirming theory.

The implications of this are likely to be significant for flood risk around the world. It’s true that 7% per degree doesn’t sound like much. But if we continue to follow the current trajectory of greenhouse gas emissions, we can probably expect in the order of three to five degrees of warming by the end of the 21st century. If the relationship between extreme rainfall and atmospheric temperature continues to hold, then this could mean as much as a 35% increase in extreme rainfall intensity on average globally.

What does this mean for the capacity of our infrastructure to handle current and future floods? Most flood-defence infrastructure, such as dams, levees, stormwater systems and coastal flood defences, has been designed to handle historical flood risk. If the risk of flooding increases, then such infrastructure will have increasing difficulty managing floods in the future. This would either lead to increased damage costs due to the flooding, or necessitate expensive infrastructure upgrades or resettlement of low-lying communities. Even the increase in extreme rainfall intensity observed thus far is likely to lead to substantial challenges for some existing infrastructure.

Nevertheless our analysis should not be interpreted as suggesting that the rapid increase in flood damage which has occurred over the past few decades is entirely attributable to climate change.

In fact, other changes such as deforestation, rapid urbanisation and an increase in the number of people living in flood plains are likely to account for the bulk of these changes. Furthermore, not all floods are caused by extreme rainfall events. Snow melt and storm surge also contribute to overall flood risk. Antecedent moisture – the wetness of the catchment prior to the flood-producing rainfall event – can also have a substantial influence on flood risk. In some parts of Australia this might even cause flood risk to decrease because of an expected increase in the number or severity of future droughts.

Despite all these caveats, our recent study contributes to the debate on how climate change will affect flood risk, by showing that the intensification of rainfall extremes is not just a projection made by climate models. Rather, it can already can be detected in our observational record.

Seth Westra receives funding from the Australian Research Council, CSIRO, Engineers Australia, Geoscience Australia and AusAid.

The Conversation

This article was originally published at The Conversation.
Read the original article.

Video: Everything was on fire, everywhere: heat, bush-fires and climate change down under

Yes, the very first WtD video

For some time I’ve been considering making short videos exploring climate change, scepticism and related environment issues. This is the first in the proposed series (I hinted these would be coming in a December post).

The above video explores the link between the Australia’s extraordinary summer of heatwaves and fire. What we are experiencing is what the science predicted.

Most of all I wanted to tell a story: of what it means to be an Australian at this point in history, knowing a little something about the science of climate change and seeing scientific predictions play out. It’s about watching the land burn while the planet warms. 

Comments welcome. 

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