The State of the Climate Report 2024 from a consortium of scientists in mulitple institutions paints a grim picture for the direction of climate change with rising temperatures and greenhouse gas emissions. To quote an opening section of the report -
“We
are on the brink of an irreversible climate disaster. This is a global
emergency beyond any doubt. Much of the very fabric of life on Earth is
imperiled. We are stepping into a critical and unpredictable new phase of the
climate crisis. For many years, scientists, including a group of more than
15,000, have sounded the alarm about the impending dangers of climate change
driven by increasing greenhouse gas emissions and ecosystem change (Ripple et
al. 2020). For half a century, global warming
has been correctly predicted even before it was observed—and not only by
independent academic scientists but also by fossil fuel companies (Supran et
al. 2023). Despite these warnings, we are
still moving in the wrong direction; fossil fuel emissions have increased to an
all-time high, the 3 hottest days ever occurred in July of 2024.”
The graphs below from the report (figure 2) categorically demonstrate the upwards trends across a whole range of measures such as carbon dioxide emissions, methane emissions, nitrous oxide emissions, ocean heat, ocean levels and so on.
Tuesday 5 November 2024 is the formal election day for the US Presidential election with Kamala Harris (Democratic Party, current US Vice President) and Donald J Trump (Republican Party, former US president) as the contenders. At the same time, 34 Senate seats and all 435 seats in the House of Representatives in the US Congress are also being decided. There are also 12 gubernatorial elections taking place making it a particularly critical moment in the US voting cycle and potentially momentuous for the United States and the wider world.
The two contenders offer radically different perspectives on the United States with Harris reflective of the future and a positive, hopeful message. Trump in contrast has continued a long history of listing deficiencies, conspiracies and claims of one form of grievance or another. Trump has also been the subject of a range of prosecutions, a number of which are not resolved and others resulted in convictions. The contrast between the two candidates could not be more extreme yet despite this situation, Trump at this point could easily win the election. There are also concerns with the public opinion polling by various organisations including media companies, that Trump's support may be underestimated. Only the election results will show whether this is correct or not.
The US is one of the most partisan divided countries at present with the majority of states either voting/aligning with the Republicans or the Democrats leaving a small number of 8 states being termed the 'swing states'. These are -
Pennsylvania
Georgia
Nebraska District 2
North Carolina
Michigan
Arizona
Wisconsin
Nevada
The margins in these states are paper thin. The US election system also has a number of in-built deficiencies such as: voluntary voting (almost 40 % of eligible voters do not vote in the Presidential ballot and almost 50 % of eligible voters do not vote for the ballots for seats in Congress); different voting systems used in different states and subject to local political influence; no limits campaign funding and little control on the truthfulness or accuracy of claims made; an electoral college system where for most states, the candidate with the most ballot votes (a bare majority) is given all that State's electoral college votes (a winner-takes-all-approach) even where the winning candidate may not be supported by the majority of Americans on a country wide basis. The stakes could not be higher for the US and for the rest of the World.
The next Conference of the Parties (COP) of the United Nations Framework Convention on Climate Change (UNFCCC) will take place in Baku, Azerbiajan from 11th November to 22nd November 2024. There are 198 Parties (197 countries plus the European Union) to the Convention representing near complete, universal membership. The Conference is held annually and rotated between the five United Nations regions ensuring that both developed and developing nations have a role for the Conference presidency. Despite the extraordinary international coverage and the near agreement on the reality of climate change including the major industrial powers of the US and China, progress to limit increased temperatures through reductions in CO2 emissions is failing at this point in time.
A string of reports from multiple academic and science institutions, from the IPCC, from Meterological agencies and from think tanks all confirm increasing temperatures, continuing and in some case increased CO2 emissions and worryingly, methane emissions. The planet continues to heat with the results being seen in a myriad of extreme weather events together with melting glaciers, melting permafrost in the Northern Hemisphere, and loss of ice cover in both the Arctic and Antarctic regions. Corresponding sea level rises are now being tangibly seen in low level land masses affecting multiple island communities in the Indian Ocean and the Pacific Ocean.
Representatives from the various countries who have signed onto the UNFCCC need to actually face the fact that they need to do more and do it earlier. The end point for results to be seen has been publicly stated as no later than 2030 otherwise a very different planet will come into existence and one that the human species will find it hard to survive on.
You don’t have to look far to see what climate change is doing to the planet. The word “unprecedented” is everywhere this year.
We are seeing unprecedented rapidly intensifying tropical storms such as Hurricane Helene in the eastern United States and Super Typhoon Yagi in Vietnam. Unprecedented fires in Canada have destroyed towns. Unprecedented drought in Brazil has dried out enormous rivers and left swathes of empty river beds. At least 1,300 pilgrims died during this year’s Hajj in Mecca as temperatures passed 50°C.
Unfortunately, we are headed for far worse. The new 2024 State of the Climate report, produced by our team of international scientists, is yet another stark warning about the intensifying climate crisis. Even if governments meet their emissions goals, the world may hit 2.7°C of warming – nearly double the Paris Agreement goal of holding climate change to 1.5°C. Each year, we track 35 of the Earth’s vital signs, from sea ice extent to forests. This year, 25 are now at record levels, all trending in the wrong directions.
Humans are not used to these conditions. Human civilisation emerged over the last 10,000 years under benign conditions – not too hot, not too cold. But this liveable climate is now at risk. In your grandchild’s lifetime, climatic conditions will be more threatening than anything our prehistoric relatives would have faced.
Our report shows a continued rise in fossil fuel emissions, which remain at an all-time high. Despite years of warnings from scientists, fossil fuel consumption has actually increased, pushing the planet toward dangerous levels of warming. While wind and solar have grown rapidly, fossil fuel use is 14 times greater.
This year is also tracking for the hottest year on record, with global daily mean temperatures at record levels for nearly half of 2023 and much of 2024.
Next month, world leaders and diplomats will gather in Azerbaijan for the annual United Nations climate talks, COP 29. Leaders will have to redouble their efforts. Without much stronger policies, climate change will keep worsening, bringing with it more frequent and more extreme weather.
Bad news after bad news
We have still not solved the central problem: the routine burning of fossil fuels. Atmospheric concentrations of greenhouse gases – particularly methane and carbon dioxide – are still rising. Last September, carbon dioxide levels in the atmosphere hit 418 parts per million (ppm). This September, they crossed 422 ppm. Methane, a highly potent greenhouse gas, has been increasing at an alarming rate despite global pledges to tackle it.
Compounding the problem is the recent decline in atmospheric aerosols from efforts to cut pollution. These small particles suspended in the air come from both natural and human processes, and have helped cool the planet. Without this cooling effect, the pace of global warming may accelerate. We don’t know for sure because aerosol properties are not yet measured well enough.
Other environmental issues are now feeding into climate change. Deforestation in critical areas such as the Amazon is reducing the planet’s capacity to absorb carbon naturally, driving additional warming. This creates a feedback loop, where warming causes trees to die which in turn amplifies global temperatures.
Loss of sea ice is another. As sea ice melts or fails to form, dark seawater is exposed. Ice reflects sunlight but seawater absorbs it. Scaled up, this changes the Earth’s albedo (how reflective the surface is) and accelerates warming further.
In coming decades, sea level rise will pose a growing threat to coastal communities, putting millions of people at risk of displacement.
Accelerate the solutions
Our report stresses the need for an immediate and comprehensive end to the routine use of fossil fuels.
It calls for a global carbon price, set high enough to drive down emissions, particularly from high-emitting wealthy countries.
Introducing effective policies to slash methane emissions is crucial, given methane’s high potency but short atmospheric lifetime. Rapidly cutting methane could slow the rate of warming in the short term.
Natural climate solutions such as reforestation and soil restoration should be rolled out to increase how much carbon is stored in wood and soil. These efforts must be accompanied by protective measures in wildfire and drought prone areas. There’s no point planting forests if they will burn.
Governments should introduce stricter land-use policies to slow down rates of land clearing and increase investment in forest management to cut the risk of large, devastating fires and encourage sustainable land use.
We cannot overlook climate justice. Less wealthy nations contribute least to global emissions but are often the worst affected by climate disasters.
Wealthier nations must provide financial and technical support to help these countries adapt to climate change while cutting emissions. This could include investing in renewable energy, improving infrastructure and funding disaster preparedness programs.
Internationally, our report urges stronger commitments from world leaders. Current global policies are insufficient to limit warming to 1.5°C above pre-industrial levels.
Without drastic changes, the world is on track for approximately 2.7°C of warming this century. To avoid catastrophic tipping points, nations must strengthen their climate pledges, reduce dependence on fossil fuels, and accelerate the transition to renewable energy.
Immediate, transformative policy changes are now necessary if we are to avoid the worst effects of climate change.
Climate change is already here. But it could get much, much worse. By slashing emissions, boosting natural climate solutions and working towards climate justice, the global community can still fend off the worst version of our future.
In January 2023, a new comet was discovered. Comets are found regularly, but astronomers quickly realised this one, called C/2023 A3 (Tsuchinshan-ATLAS), had the potential to be quite bright.
Some hyperbolic reports have suggested it might be the “comet of the century”, but any astronomer will tell you the brightness of comets is notoriously hard to predict. As I explained last year, we’d have to wait until it arrived to be sure how bright it would become.
Now, the time has come. Comet C/2023 A3 is currently visible with the naked eye in the morning sky in Australia and Aotearoa New Zealand, with its best yet to come in the next few weeks. And it does look promising. It’s unlikely to be the comet of the decade (never mind the comet of the century), but it will almost certainly become the best comet of the year.
So where, and when, should you look to get your best views of this celestial visitor?
A show in the morning, before sunrise
At the moment, comet C/2023 A3 (Tsuchinshan-ATLAS) is a morning object, rising around an hour and a half before sunrise. It is visible to the naked eye, but not yet spectacular. However, with binoculars you can easily see the comet’s dusty tail pointing away from the Sun.
The comet will remain at about the same altitude in the morning sky until around September 30. It will then get closer to the horizon on each consecutive morning until it’s lost in the glare of the approaching dawn by October 6 or 7.
If you want to spot the comet in the morning sky, look east. The sliders below will help you orient yourself and choose the best time to look, depending on your latitude.
During this period, the comet should slowly brighten. It reaches its closest approach to the Sun (perihelion) on September 27, when it will be 58 million kilometres from our star.
As it swings around the Sun, it will continue to approach Earth, and so should continue to brighten. The best show in the morning sky will likely be during the last couple of days of September and the first few days in October, before the comet is lost to view.
This could cause a spectacular brightening of the comet, thanks to “forward scattering” caused by its dust. Imagine looking towards a bright light source through a cloud of dust grains. The grains nearest to the light source will scatter light from the source back towards you.
As the comet swings between Earth and the Sun, it will be perfectly placed for this forward scattering process to occur. If the comet is particularly dusty, this could cause its apparent brightness to increase by up to 100 times.
If it does, there’s a small chance the comet could briefly become visible in the daylight sky on October 9 and 10.
However, it will be very close to the Sun in the sky, and incredibly hard to spot. Only the most experienced observers may be able to detect the comet at this time, and it requires a special technique. Do not try to stare at the Sun to see it.
The best show could be after October 12
After swinging between Earth and the Sun, the comet will appear in the evening sky. It will rapidly climb in the western sky, and should be a bright, naked-eye object for a few days from October 12. The sliders below will give you a sense of where to look.
For the first few days of this period, the comet will still benefit from the forward scattering of sunlight, but this will decrease as it moves away.
What about the tail?
The positioning of the comet, Earth and the Sun in the Solar System means the comet’s tail will be streaming outwards, past our planet. This means it could grow to prodigious lengths in the night sky.
The bulk of that tail will likely be too dim to see easily with the naked eye, but it could be a fantastic spectacle for photographers. Expect to see a wealth of comet images flooding the internet around the middle of October.
As the days pass and the comet climbs higher, it will fade quite rapidly. It will likely become too faint to see with the naked eye, even for seasoned and experienced observers, before the end of October.
At that point, the show will be over. Comet C/2023 A3 (Tsuchinshan-ATLAS) will continue to flee the inner Solar System, moving into the icy depths of space, never to return.
But remember the classic saying – comets are like cats. They have tails and will often surprise us. For now, comet C/2023 A3 is behaving itself. It’s brightening predictably, and putting on a good show.
But comets that approach this closely to the Sun often fragment. This is impossible to predict, and far from guaranteed. If the comet did break up, it could become even more spectacular because of all the dust and gas it would release.
The opposite could still happen, too. The comet could fail to brighten as much as we expect, although that seems unlikely at this stage.
Whatever happens, we’re in for a fascinating few weeks of comet watching. Hopefully, a real spectacle awaits us.
Thousands of protesters have been out in force in Melbourne this week to disrupt the Land Forces International Land Defence Exposition, where defence companies from around the world are showcasing their latest designs in weapons and technology.
The activists are protesting the use of such weapons – in particular, allegations of use against Palestinian civilians by Israeli forces in Gaza.
With the expo in Melbourne this week, there is also renewed attention on Australia’s weapons exports and imports. So, how much do we know about where Australia is sending its arms, and how many arms it is importing?
What gets reported?
The government limits what information is made publicly available about arms exports and imports due to both security and commercial reasons.
Australian exports include both military-specific and dual-use goods and technologies, such as computer components used in weapons. There is a strict export control system that is intended to prevent weapons from getting into the hands of our adversaries and to ensure they meet our obligations under international law.
But this system has been criticised for being opaque. This is because Australia only publicly reports recipient countries for items it is obliged to disclose under the Arms Trade Treaty, or in some cases, during parliamentary hearings or other similar processes.
Separately, Australia’s Defence Export Office publishes quarterly reports with very basic information, such as the number and types of export applications it receives and the total value of permits it issues. It only specifies the export permits for “end users” by continent, not country.
In the year 2023–24, the office finalised more than 4,000 export defence permits, with the value of permits issued exceeding an estimated A$100 billion.
Unlike other countries, Australia does not specify exactly what types of goods it has approved for import or export.
The government also does not report how many issued permits are actually used by companies to trade goods. The movement of military goods to and from Australia is tracked through other processes, such as customs controls.
Finally, requests for further information are typically met with resistance from the government, on the basis such disclosures would breach security or commercial confidentiality arrangements.
However, while not authoritative, information about Australian exports can be pieced together from a variety of sources. This includes reports from exporting companies themselves, reports sent by exporters to the Department of Foreign Affairs and Trade, and statements made in parliament and in other governmentreporting.
The Stockholm International Peace Research Institute (SIPRI) also tracks arms shipments between countries by assessing public information. Some countries provide information directly to their analysts.
Here is some data we have compiled from SIPRI showing Australia’s exports and imports for the most recent five-year period from 2019–23, based on what is publicly known.
Australia’s arms exports
According to SIPRI, Australia ranked 13th in overall military expenditures globally in 2022–23, spending US$32.3 billion (A$49 billion), or about 1.9% of GDP.
Australia was also one of the top 20 arms exporters in the world from 2019–23, though its share of total global arms exports was just 0.6%, similar to Canada. This share was up from 0.3% in 2014–18.
The United States, meanwhile, accounted for 42% of global arms exports in 2019–23.
The map below shows the top recipients for Australian arms during this five-year period. The top three recipients were Canada (32% of Australia’s total exports), Chile (28%) and the United States (11%).
What do we know about Israel?
According to SIPRI, Israel’s arms imports for 2019–23 came primarily from the US (69%) and Germany (30%).
The Albanese government maintains Australia hasn’t supplied weapons or ammunition to Israel in the past five years. This week, it also explicitly backed the United Kingdom’s decision to curb arms exports to Israel.
In June, the government said it had granted eight permits to export defence-related equipment to Israel since the Gaza war began last October. It clarified that most of the items were being sent to Israel for repair and then returned to Australian defence and law enforcement for their use.
This reporting, however, does not capture sub-components that are manufactured in Australia and sent to a central repository overseas to be used in a larger platform, like an F-35 jet, which can then be sent to Israel from the US or Europe.
Parts made in Australia are used in the US to build the F-35, which is then sold globally.CC BY-SA
According to SIPRI, the largest sources of military goods to Ukraine have been the US, Germany and Poland.
Australia’s arms imports
SIPRI’s data shows that Australia was eighth-largest importer of arms from 2019–23, accounting for 3.7% of global arms imports.
The vast majority (80%) of its imports during this period came from the United States, followed by Spain at 15%.
The types of items that Australia has reported importing from the US include ships, aircraft, helicopters and missile defence systems. In addition, SIPRI noted that Australia ordered 300 long-range missiles from the US in 2023.
However, because it often takes years for these large defence items to be built, quite often there is a lag in the reporting of import data.
For example, Australia’s recently announced deal with Hanwha, a Korean defence company, to build artillery and armoured vehicles will not be featured in these statistics as some components of the vehicles and artillery will be built in a factory in Geelong, Australia, while others will not be delivered in this reporting period.
Also, while export control measures deal with goods that are built elsewhere and brought to Australia, some permits are required to import the know-how to build controlled defence goods in Australia. This is another reason imports like these might not appear on public reports.
Launched in 2011, NASA’s NEOWISE mission operated in Earth’s orbit until late last week. It detected more than 3,000 near-Earth objects or NEOs – asteroids or comets whose orbits can bring them close to Earth, even with the possibility of a collision. NEOWISE was shut down on August 8.
Surveying the population of NEOs is central to the emerging concept of planetary defence. That is, understanding and mitigating the risk of collision from asteroids large enough to do significant damage to Earth.
NEOWISE has made fundamental contributions to establishing the knowledge base for planetary defence, with more than 200 of the 3,000 objects it studied not known to us previously.
Now at mission end, and commanded by NASA to shut itself down, NEOWISE will re-enter Earth’s atmosphere before the end of this year. Where does that leave us with defending our planet?
All Known Asteroids in the Solar System (1999–2018)
Infrared means “beyond red” – infrared light sits just past the red end of the spectrum of colours humans can see. We know infrared radiation better as the heat from the Sun, for example, or from a radiator keeping us warm in winter.
Infrared light is just outside the part of the spectrum that the human eye can see.brgfx/Shutterstock
When the coolant on the WISE mission ran out and these sensitive observations of galaxies couldn’t be carried out any more, NASA granted a mission extension under the NEOWISE name. They realised the telescope system was still sensitive enough to detect asteroids and comets that come close to Earth and the Sun, thereby having a very strong infrared signal.
NASA has an extraordinary history of squeezing extra life out of missions that reach completion. In this case, NEOWISE represented an entire second life, in an entirely different area of research.
How will we defend Earth now?
As well as the discovery and study of thousands of NEOs, NEOWISE established the foundation of knowledge that has informed a new, dedicated planetary defence mission. NASA’s NEO Surveyor will be launched in 2027.
NEO Surveyor’s goal is to discover approximately two thirds of all NEOs larger than 140 metres in diameter, over a five year baseline survey. This is a big step toward fulfilling the mandate United States Congress has provided to NASA: to discover 90% of all NEOs in this size range.
If they hit Earth, asteroids of this size could cause mass casualties if the impact were over a large metropolitan region.
You might think this poses a bit of a risk – shutting down NEOWISE three years before launching NEO Surveyor. What happens if one of these big asteroids comes our way in the next few years?
The risks are very small, as estimates show asteroids 140 metres in diameter impact Earth only approximately every 20,000 years. So, we would have to be extremely unlucky to have one in any given three-year period, especially impacting a place that would cause a large amount of damage. Only around 3% of Earth’s surface is occupied by urban areas.
NASA doesn’t really have much of a choice with the end of NEOWISE. The Sun’s 11-year activity cycle is picking up and causing Earth’s upper atmosphere, the ionosphere, to thicken. NEOWISE is flying through this ionosphere and can’t raise its orbit, so the ionosphere is inevitably dragging NEOWISE back to Earth.
NEO Surveyor started construction in 2023, so a 2027 launch is pretty impressively rapid, which is minimising the gap between NEOWISE and NEO Surveyor.
NEOWISE is scheduled to enter Earth’s atmosphere before the end of the year, but we don’t know precisely when.
Weighing almost 700kg, some of NEOWISE itself is likely to impact the surface of Earth. Hopefully it stays away from populated areas in the process – some recent re-entry events have resulted in space debris falling reasonably close to populated areas.
An asteroid is coming! What next?
Knowing about an asteroid on a collision course with Earth is one thing. Doing something about it is another thing altogether.
Huge steps toward planetary defence occurred two years ago, when the DART mission flew to an asteroid, impacted it, and changed its trajectory. This demonstrated it’s possible to change the course of asteroids, which could be used in the future to protect Earth from a collision.
Predicting potential Earth impacts as far as possible in advance, years preferably, gives the DART-style technology approach a chance.
The pioneering work of NEOWISE, and the upcoming comprehensive observations of NEO Surveyor, will place an enormous amount of information in our scientific bank, which will never go out of date and will be the basis for planetary defence for perhaps hundreds of years into the future.
