Monday 17 July 2023

Climate Change State of Play in 2023: as seen from Yamba, Australia and the rest of the world

 

Yamba (pop. est. 6,388) at the mouth of the Clarence River estuary on the NSW far north coast, has an official weather station ID: 058012 which has been recording observations since May 1877 from a headline on the northside of the town.


What this relatively long history, of measuring air temperature, humidity levels, wind direction & velocity along with rainfall, is currently indicating is that from January to June 2023 monthly temperatures have been hotter than the 145 year averages.


While over the same period rainfall is so far below monthly averages that by June - the first month of Winter - rainfall was est. 125-127mm below the 145 year average for that month and occurred across only 7 of the 30 June days.


Yamba, like much of the Clarence Valley and 23.3% of the North Coast has been classified as Drought Affected on the NSW DPI Combined Drought Indicator (CDI).


NSW DPI CDI mapping as of 12 July 2023














Reading the Australian Bureau of Meteorology (BOM) webpages, it is looking increasingly likely that an El Niño event will be declared in the southern hemisphere before September 2023.


It seems that little Yamba and Australia are marching in step with the rest of the world.......


Washington Post, 13 July 2023:


The world is hotter than it’s been in thousands of years, and it’s as if every alarm bell on Earth were ringing.


The warnings are echoing through the drenched mountains of Vermont, where two months of rain just fell in only two days. India and Japan were deluged by extreme flooding.


They’re blaring from the scorching streets of Texas, Florida, Spain and China, with a severe heat wave also building in Phoenix and the Southwest in coming days.


They’re burbling up from the oceans, where temperatures have surged to levels considered “beyond extreme.”


And they’re showing up in unprecedented, still-burning wildfires in Canada that have sent plumes of dangerous smoke into the United States.


Scientists say there is no question that this cacophony was caused by climate change — or that it will continue to intensify as the planet warms. Research shows that human greenhouse gas emissions, particularly from burning fossil fuels, have raised Earth’s temperature by about 1.2 degrees Celsius (2.2 Fahrenheit) above preindustrial levels. Unless humanity radically transforms the way people travel, generate energy and produce food, the global average temperature is on track to increase by more than 3 degrees Celsius (5.4 Fahrenheit), according to the Intergovernmental Panel on Climate Change — unleashing catastrophes that will make this year’s disasters seem mild.


The only question, scientists say, is when the alarms will finally be loud enough to make people wake up.


This is not the new normal,” said Friederike Otto, a climate scientist at Imperial College London. “We don’t know what the new normal is. The new normal will be what it is once we do stop burning fossil fuels … and we’re nowhere near doing that.”….


Read the full article here.


The Sydney Morning Herald, 14 July 2023, p 22:


Natural disasters and extreme weather are thrashing the northern hemisphere as temperature records rapidly topple. Floods are overwhelming parts of Asia and Europe, fires are ravaging the US, sea surface temperatures off Europe are the hottest on record and the global average temperature has been at a record high four times in the past week.


Drought is sapping northern parts of China and heatwaves are paralysing cities at the same time deadly floods displace thousands in the south. It's just a taste of what's to come as climate change worsens.


Marine heatwaves


The ingredients for the catastrophic weather events in the northern hemisphere have been brewing in global oceans for months. In the lead-up to Earth's hottest week in recorded history, between July 3 and 9 this year, 40 per cent of the world's oceans were stewing through severe marine heatwaves.


"A big part of the fact that we've got these records occurring is because the oceans are so warm," said marine heatwave expert Associate Professor Alex Sen Gupta from UNSW's Climate Change Research Centre. "It means it's very likely that this is going to be the warmest year on record."


Much of the North Atlantic suffered the most extreme marine heatwaves in history. National Oceanic and Atmospheric Administration called a Category 5 (beyond extreme) heatwave in waters west of Ireland as temperatures climbed 5 degrees above the June average.


The record marine heat in the Atlantic spurred the formation of Tropical Storm Bret, the most eastward ever tropical storm this early in the year. Bret churned westward and swept through the Caribbean, damaging water infrastructure in Barbados and shuttering schools in St Lucia.


The ocean heatwaves have a high chance of holding strong for months, potentially contributing to bursts of damaging rain or intensifying heatwaves in Britain and Europe; one of either extremes. The warm water will mix deeper down into the ocean and have global effects - including on Arctic sea ice - for months.


The National Oceanic and Atmospheric Administration (NOAA) predicts that by September, 50 per cent of the world's oceans could be experiencing marine heatwaves. The normal global rate is 10 per cent.


Weatherzone meteorologist Yoska Hernandez said the sea surface temperatures off Australia are the warmest on record, about 0.3 to 0.5 degrees warmer than last year.


Warm oceans are particularly concerning because they increase moisture in the atmosphere, which can lead to more intense rain events. In the past two weeks, major floods have swept across the US, China, Japan, Europe and Pakistan. Hernandez said the drivers behind the rain events were all separate, but all occurred in the context of climate change.


For example, the Pakistan event has been the result of seasonal monsoonal rains, with as much as six months' of rain falling in 18 hours over some cities.


The floods in the north of America have been driven by an intense front moving over the region, dumping a lot of rain. There's a lot of moisture in the atmosphere driven by the warming ocean temperatures.


In Spain, a large thunderstorm has resulted in flash flooding across Zaragoza in the country's northeast - with about 64mm falling over some parts in a few hours. This is almost the average rainfall during summer for the country.


Last week, there were four days in which Earth's average temperature reached record highs. The global average temperature hit 17.2 degrees on Thursday, July 6, surpassing the 17.18-degree record set on July 4 and equalled on July 5, according to data from the University of Maine's Climate Reanalyser. The previous record of 17.01 degrees was set on Monday, July 3.


The data relies on satellite information and computer simulations to measure the world's condition. It is, however, worth noting NOAA said it could not yet validate the data but that the agency recognised the warm period was due to climate change.


"Combined with El Niño and hot summer conditions, we're seeing record warm surface temperatures being recorded at many locations across the globe," the agency said last week.


The World Meteorological Organisation, a specialised agency of the UN, declared the El Niño event last week. It's one of the most important drivers of unusual weather over the entire globe. In the southern hemisphere, El Niño tends to have a drying effect, but in the northern hemisphere it can increase rainfall.


For most of Australia, El Niño brings dry weather, increasing bushfire risk. But in other parts of the world it leads to wetter conditions, as in southern America.


The Bureau of Meteorology is yet to formally declare an El Niño event, but is expected to do so in the coming weeks. The agency has different criteria than other international weather agencies.


Sen Gupta said it was unusual so many weather events associated with El Niño, including fires and marine heatwaves, were striking before the weather system had even formed (the system has a 90 per cent chance of fully taking hold in the second half of the year).


Countries including Australia were warned to prepare for bad fire seasons. North America is currently in the midst of its most catastrophic fire season ever, which has seen nearly 4000 fires tear across Canada. Smoke spewed from the incineration of 9.5 million hectares and caused the worst air pollution in large swathes of the US in recorded history, draping cities such as New York in orange clouds of smog last month.


Last week in Beijing, as heat records topple across Asia, the government ordered a pause in outdoor work as the city hit a 10-day streak of days above 35 degrees, at the same time floods carried off cars and destroyed buildings, killing at least a dozen people and displaced thousands more in central and southern China.


Pinpointing the effect of climate change on one weather event is a difficult science, but a network of global researchers from the World Weather Attribution zeroed in on a four-day heatwave that killed 13 people. They concluded that human-induced climate change made the deadly heat 30 times more likely. (Another 96 people died from heat-related conditions in India in June.)


Tipping point


It's a question we keep coming back to as records tumble.


Dr Nandini Ramesh, a senior research scientist at CSIRO Data61, said it's important to understand what a tipping point is.


"A tipping point is when you push something until it can't be undone and it exacerbates further warming. An example is the west Antarctic ice sheet collapsing, which would cause irreversible effects on ocean circulation and climate," she said…..


"The ocean will [have] almost constant marine heat waves if we keep on pumping carbon dioxide into the atmosphere. We have to continually update what we class as a marine heatwave or, or go to more extreme definitions."


More than 61,000 people died because of last year's brutal summer heat waves across Europe, according to a study in the journal Nature Medicine. The findings suggest that two decades of efforts in Europe to adapt to a hotter world have failed to keep up with the pace of global warming. Extreme heat had been expected that summer based on how much the planet had warmed in the past decade, the report notes. This trend is likely to continue.


"Having a warmer atmosphere makes both intense rain and heat waves worse," Ramesh said. "It will push us into temperatures that are dangerous to the human body."


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