Climate explained: what each of us can do to reduce our carbon footprint



Eating less meat is one change many of us can make to reduce our contribution to climate change.
from http://www.shutterstock.com, CC BY-ND

Nick Golledge, Victoria University of Wellington


CC BY-ND

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

As an individual, what is the single, most important thing I can do in the face of climate change?

The most important individual climate action will depend on each person’s particular circumstances, but each of us can make some changes to reduce our own carbon footprint and to support others to do the same.

Generally, there are four lifestyle choices that can make a major difference: eat less or no meat, forego air travel, go electric or ditch your car, and have fewer children.

In New Zealand, half of our greenhouse gas emissions come from agriculture. This is more than all transport, power generation and manufacturing industries combined. Clearly the single biggest change an individual can make is therefore to reduce meat and dairy consumption. A shift from animal to plant-sourced protein would give us a 37% better chance of keeping temperature rise under 2℃ and an almost 50% better chance of staying below 1.5℃ – the targets of the Paris agreement.

Best of all, this can be done right now, at whatever level you can manage, and there are many people taking this step.

One aspect that is often overlooked is that carnivorous pets (mainly dogs, cats) consume lots of meat, with all the associated impacts described above. A recent US study concluded that dog and cat ownership is responsible for nearly one third of the environmental impacts associated with animal production (land use, water, fossil fuels). So ideally, if you’re getting a new pet, go for something herbivorous.

Buy locally, eat seasonally

Buy local produce, whether it’s food grown locally or goods manufactured locally rather than imported from overseas. Goods that are transported around the world by sea account for 3.3% of global carbon dioxide emissions and 33% of all trade-related emissions from fossil fuel combustion, so reducing our dependence on imports makes a big difference to our overall carbon footprint.

Car use is a problem, because we all enjoy the personal mobility cars provide. But it comes with an excessively high carbon cost. Using public transport where possible is of course preferable, but for some the lack of personal freedom is a big disadvantage, as well as the sometimes less than perfect transit networks that exist in many parts of the country.

One alternative for many people looking to commute short distances might be an e-bike, but think of it as an alternative to your car rather than a replacement for your bike. For those looking to replace their car, buying a hybrid or full electric model would be the best thing from an emissions perspective, even if the production of the cars themselves isn’t entirely without environmental problems.

New Zealand’s network of electric vehicle (EV) chargers is growing rapidly, but generally speaking it is easiest to charge at home if you’re doing daily commutes. This becomes economical if you have an electricity supplier offering a special low rate for EV charging.

On the subject of electricity, an easy and quick way to reduce your carbon footprint is to switch to a supplier that generates electricity only from renewable sources. In New Zealand, we have an abundance of renewable options, from solar, wind and hydro.

Plant trees

Planting trees requires having some space, but if you have land available, planting trees is a great way to invest in longer-term carbon sequestration. There is a lot of variability between species, but as a rule of thumb, a tree that lives to 40 or 50 years will have taken up about a ton of carbon dioxide.




Read more:
Climate explained: why plants don’t simply grow faster with more carbon dioxide in air


Air travel is, for many of us, an essential part of our work. There is some progress in the field of aviation emissions reductions, but it is still a long way off. In the short term we have to find alternatives, whether that is in the form of teleconferencing or, if travel is essential, carbon offsetting schemes (although this is far from a perfect solution unfortunately).

Vote for climate-aware politicians and council representatives. These are the people who have the power to implement changes beyond the scope of individual actions. Make your voice heard through voting, and by contributing to discussion and consultation processes.

Community initiatives such as tree planting or shared gardens, or just maintaining wild spaces are ideal for carbon sequestration. This isn’t just because of the plants these spaces accommodate, but also because of the soil. Globally, soil holds two to three times more carbon than the atmosphere, but the ability of soil to retain this depends on it being managed well. Generally speaking, the longer and more densely planted an area of soil is, the better it will sequester carbon.

How to cope

One of the frustrations is the realisation that climate change is not something that can be left to politicians to deal with on our behalf. The urgency is simply too great. The responsibility has been implicitly devolved to the individual, without any prior consent.




Read more:
The rise of ‘eco-anxiety’: climate change affects our mental health, too


But individual actions are massively important in two ways. First, they have an immediate impact on our total carbon footprint, without any of the inertia of political machinations. Secondly, by adopting and advocating for low-carbon life choices, individuals are sending a clear message to political leaders that a growing proportion of the voting population will favour policies that are aligned with similar priorities.

It is of course hard to stand your ground and stick with new lifestyle choices when you feel surrounded by people who choose not to change, or worse, actively mock and criticise. This is normal human psychology. People subconsciously tend to feel attacked if they see someone else making a so-called ethical or moral choice, as if they themselves are being judged, or criticised.

In the context of climate change, the science is so overwhelmingly clear, and the current and future impacts so manifestly important, that not to acknowledge this in a meaningful manner either reflects a lack of understanding or awareness, or is simply selfish. Rather than taking issue with those members of society, a more positive approach that can help you cope with the feeling of marginalisation is to actively seek out like-minded people.The Conversation

Nick Golledge, Associate Professor of Glaciology, Victoria University of Wellington

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

Winter storms are speeding up the loss of Arctic sea ice



A scientist checks cracks in the Arctic sea ice after a storm (April 2015, N-ICE2015 expedition).
Amelie Meyer/NPI, Author provided

Amelie Meyer, University of Tasmania

Arctic sea ice is already disappearing rapidly but our research shows winter storms are now further accelerating sea ice loss.




Read more:
Arctic breakdown: what climate change in the far north means for the rest of us


The research is based on data we gathered during an expedition on a small Norwegian research vessel, the Lance, that was left to drift in the Arctic sea ice for five months in 2015.

Time series of air temperature anomalies in the Arctic for the period 1981-2010: Temperatures in the Arctic in May and June 2019 period were the warmest in the satellite records.
Zack Labe (@ZLabe)

The expedition was intense and felt more like going to the Moon than going on a typical research cruise. What took us by surprise were the many winter storms that battered the ice (and our ship and ice camp).

It has taken us years to collate these data but now we know the winter storms play a key role in the fate of Arctic sea ice, particularly in the Atlantic sector of the Arctic.

Norwegian research vessel ‘Lance’ frozen in the Arctic sea ice in February 2015 during the N-ICE2015 expedition.
Paul Dodd (NPI)

How winter storms amplify climate change

On average, about 10 extreme storms will reach all the way to the North Pole each winter. While these winter storms are short (they last on average 6-48 hours), they can be incredibly intense.

During a storm in winter 2015 we saw the air temperature rise from -40℃ (-40℉) to 0℃ (32℉) in just a day, and then fall back to -30℃ (-22℉) the next day, when cold Arctic air returned after the storm.

These storms bring heat, moisture and strong winds into the Arctic, and next we look at how they impact sea ice and its surroundings.

Warming and weakening the ice

The heat from the storms warms up the air, snow and ice, slowing down the growth of the ice. Moisture from the storms falls as snow on the ice. After the storm, the blanket of snow insulates the ice from the cold air, further slowing the growth of the ice for the remainder of winter.

The strong winds during the storms push the ice around and break it into pieces, making it more fragile and deforming it, more like a boulder field.

The strong winds also stir the ocean below the ice, mixing up warmer water from deeper waters to the surface where it melts the ice from below. This melting of the ice in the middle of winter can happen for several days after the storms when the air is already back to well below freezing.

Processes related to Arctic winter storms. In the first storm phase, strong southerly winds compress the ice cover and transport warm air, moisture, and bring strong winds. In the second phase, northerly winds transport ice southwards. After the storm has passed, cold and calm conditions return, allowing new ice to grow in leads. When the next winter storm arrives, it further drives the ice cover into a relatively thin-ice, snow-covered mosaic of strongly deformed ice floes. These new conditions impact surrounding ecosystems by shaping habitats and light conditions.
Graham et al., 2019 (Scientific Reports)

Thinner ice, shelter for life and accelerated melting

The breakup of the ice opens big passages of open water between ice floes, called leads. In winter these passages end up refreezing rapidly, generating new super-thin ice.

These thinner refrozen patches of ice let more light through in the following spring, allowing ocean plants (phytoplankton) to bloom earlier.

The rougher sea ice landscape becomes a shelter for many ice-associated Arctic organisms, including ice algae, becoming biological hot spots in the following spring.

The broken up and deformed ice drifts faster, reaching warmer waters where it melts sooner and faster.

So really, winter storms precondition the ice to a faster melt in the following spring with an impact that continues well into the following season.

Why is Arctic sea ice declining?

Winter sea ice cover in the Atlantic sector of the Arctic has been retreating at a record breaking pace, especially in the Barents Sea off Norway and Russia.

Average September Arctic sea ice extent from 1979 to 2018. Black line shows monthly average for each year; blue line shows the trend.
National Snow and Ice Data Center

The Arctic is particularly sensitive to human driven climate change. We know the decrease in sea ice is due to both the warming of the Arctic (air and ocean) and changing wind patterns that break up the ice cover.

But there are also amplifying mechanisms or “feedback” mechanisms, in which one natural process reinforces another. Their role in the decrease of sea ice is hard to predict. We now know winter storms in the Arctic contribute to these feedback mechanisms.

More storms ahead

Arctic winter storms are increasing in frequency and this is likely due to climate change.

With the thinner Arctic sea ice cover and shallower warmer water in the Arctic Ocean, the mechanisms we observed during the winter storms will likely strengthen and the overall impact of winter storms on Arctic ice is likely to increase in the future.

Two weeks ago, the Arctic sea ice reached its minimum extent for 2019, after another winter of intense winter storms. The minimum ice extent was effectively tied for second lowest since modern record-keeping began in the late 1970s, along with 2007 and 2016, reinforcing the long-term downward trend in Arctic ice extent. Arctic sea ice has been declining for at least 40 years, and amplifying mechanisms such as the winter storms are accelerating this retreat.

Arctic sea ice extent just reached its annual minimum extent for 2019 on September 18. This season was a tie for the 2nd lowest on record, along with 2007 and 2016 and behind 2012, which holds the overall record minimum.
Zack Labe (@ZLabe)

As highlighted in the recent IPCC Ocean and Cryopshere report, these changes in September sea ice are likely unprecedented for at least 1,000 years.

Remember also that changes in the Arctic don’t just affect the immediate region: Arctic warming has been linked to the polar vortex, and weather extremes across central Europe and north America.




Read more:
Microplastics may affect how Arctic sea ice forms and melts


As we start taking into account feedback mechanisms like the winter storms, our predictions for the first Arctic sea ice free summer are indicating it will likely happen before 2050.The Conversation

Amelie Meyer, Research fellow, University of Tasmania

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