Dr Nick Earl-Jones explains how climate change is linked to Carbon Dioxide emissions, and what will happen when we stop burning fossil fuels.

One of the many fascinating and wonderful things about our planet Earth is that its climate is always changing. For literally billions of years, life on Earth has been influencing the planet’s changing climate. In fact, ancient microbes caused Earth’s first ever global warming.  The earliest photosynthetic microorganisms belched out enough methane to warm the planet by 15°C. This bout of global warming may have saved Earth from freezing over and created a comfortable climate for early organisms. Other climatic changes in the Earth’s history have been triggered by the changing configuration of continents and oceans, changes in the Sun’s intensity, variations in the orbit of Earth, and volcanic eruptions.

Climate change resulting from recent and current human activities is happening much faster than it ever has before, which means that many species (including humans) are struggling to adapt to the impacts of climate change. If humanity can meet its targets for reducing greenhouse gas emissions then we can slow and even reverse the current warming trend.

So while the Earth’s climate has always been changing over very long timescales – such as glacial and inter-glacial periods – and it will continue to do so, humanity does have the power to fix the current warming trend through global action to reduce greenhouse gas emissions.

Great question.

Yes, it will.

Records from the bottom of lakes or boggy places tell us that as past climate changed over thousands of years, the vegetation changed. Some places went from being grassland in colder periods to forests in warmer periods. In some cases, the type of forest changed. In Tasmania we can see changes from rainforest to eucalypt forest and vice versa at different times.

Thinking about how some climate changes in the past left footprints helps a bit. About 4,200 years ago there was a change in climate that resulted in many human populations dying out or moving elsewhere. Many others also changed the types of crops they planted or how they farmed animals, and what animals they farmed where. People who study these kinds of events have also found a lot of abandoned villages and towns. About 8-900 years ago in southwestern USA, drought caused some settlements to be abandoned, too. The most famous of these is Mesa Verde and the deserted city still exists.

Right now, there are a lot of plants and animals that are finding it very hard to adapt to climate change because it’s happening so fast. It’s likely that at least some of these will die out (become extinct). Think about how Pencil pines on the Central Plateau behind Deloraine are doing. Quite a few have died from drought and many more died in fires in 1961 and more recently in 2016. As climate continues to change, we can expect more big hot fires that will kill these trees. Climate models also suggest that the west coast of Tasmania is likely to become drier. This will affect the Huon pine because it doesn’t like being dry. It likes having wet feet. These trees that can live for hundreds to thousands of years could disappear from Tasmania, and Tasmania is the only place they’re currently found.

As temperatures increase, we can also expect to get some of the pests that exist on the mainland. They haven’t been able to do well here before because it’s been too cold, but as it warms up, they will be much happier here. They might squeeze out (or maybe even feed on) other native species which will then have impacts on Tasmanian ecosystems for hundreds of years. If you were able to see what Tasmania looks like in 500 years, it will be very different to what it looks like now. Quite a few plant and animal species are likely to not exist while there may be species we don’t see here today.

So, climate change always leaves a footprint. We can find clues about this footprint in the environment.

Thank you for this excellent question. I am not an expert in genetics and don’t believe that there is currently any evidence of true genetic adaptation to climate change. Authors such as Donna Harraway have speculated about this in works that use writing styles similar to science fiction (e.g her book “Staying with the Trouble”). However at the moment works like this are “thought experiments” which imagine what genetic adaptation might be like, rather than science based on genetic evidence. 

There are many other ways that human societies are starting to adapt to our changing climates. Some of this change involves large-scale changes to the way societies live every day, e.g changing our power and transport systems to renewable energy rather than systems reliant on fossil fuels. For example, it’s no mean feat to change our current transport systems from petrol cars to predominantly electric vehicles.  However, countries like Aotearoa New Zealand are currently preparing their infrastructure to do just that. This is an example of large-scale adaptation.  

In terms of our bodies dealing with extremes in temperature (e.g hotter summers), there are limits to how our bodies can deal with this and still maintain a healthy core temperature. For example if we live in hotter, more humid conditions (e.g higher than 33 degrees Celsius), we would need to be careful to avoid heat exhaustion by drinking more fluids and being careful what time of the day we exert ourselves. Many people in the world already live in very hot places, and generally their housing and lifestyles reflect sensible ways to live in these conditions. It’s possible that some of these ways of life will become more common in other parts of the world if the weather is consistently warmer. 

The North Pole and Antarctica sit at opposite ends of the Earth. If you think of them just as spots on a map, then they will definitely still exist in 2040.

But, if we instead ask “Will the North Pole and Antarctica be the same in 2040 as they are today?” then the answer is a little different.

The North Pole sits in the middle of the Arctic Ocean. For centuries, this area has been covered in frozen seawater, which we call sea ice. As our world warms, the amount of ice covering the Arctic Ocean has been decreasing, especially in summer. By 2040 it’s possible that there won’t be any sea ice left in the Arctic Ocean during summer.

Antarctica isn’t just a place on a map; it’s a continent, like Australia. Although Antarctica might look a little different by 2040, it will still be there and still be covered by an ice cap that is more than two kilometres thick.

Yes. In fact, since records began about 100 years ago, the average Australian temperature has warmed but about 1.4°C. By 2050, Tasmania is projected to experience an increase in temperature of at least 1.5°C. We say at least because the real amount depends on what happens to CO2 emissions between now and then. By 2100, Tasmania is projected to experience an increase of 1.5°C to 3°C in temperature across all locations, and more than 4°C in mountain regions.

But this is the average across the year. There will also be changes in temperature extremes, like heat waves. For example, for 1961-1990, Launceston had an average of 29 days per year over 25°C. For 2070-2099, we predict that Launceston will average 75 days per year over 25°C.

Tasmania is one of the marine global warming hotspots, which is big a challenge but also a potential opportunity for the Tasmanian fishing industry. Some important Tasmanian fisheries species might become less abundant and more vulnerable to climate extremes, but other species might benefit from warmer ocean and increase in abundance. Some fish species that are moving into Tasmanian waters already are or could become valuable fisheries species. The fishing industry can be sustainable if it adapts proactively, plans for the future and also supports marine protected areas to help improve resilience of fish populations. Actually, the Tasmanian fisheries industry is one of the few in the world that have conducted risk assessments, to see how climate change might affect them, and have already started some important adaptations (like actively fishing for a pesky urchin that has moved into Tasmania now that it is warm enough for it survive, but the urchin creates a problem by eating all the kelp habitat that lobsters need!).   

One of the big questions for Tasmanian fisheries is how climate change will affect giant kelp forests. These forests are very important for fish and fisheries but are threatened by rising sea temperatures and the increasing sea urchin populations. Together with other management and fishing changes, marine protected areas could play an important role, as they help to rebuild the numbers of large fish and lobsters, which in turn keep the urchin numbers down.  

You could read more about climate change adaptation research here.