Greenhouse gas emissions (GHGs) will need to be cut back if the worst of global warming is to be avoided. So, how much GHG do we produce in our daily lives? Where can we make cuts on these emissions?
Here are some general numbers which may help us in our daily decisions. Let’s start with transportation and consider the trip from Blenheim to Christchurch and back, a distance of about 614 km on Hwy 1. One litre of petrol produces about 2.4 kg of CO2 when burned in an automobile. So, if your car uses 10 litres fuel per 100 km, each 100 km trip produces about 24 kg of CO2. Every 50 litre tank of petrol creates 120 kg of CO2. Diesel fuel produces slightly more, or about 2.7 kg CO2 per litre. So, in a vehicle using 10 litres of petrol per 100 km, would create about 147 kg of CO2.
But what if we decide to fly instead? Air New Zealand’s carbon offset calculator shows a flight to Christchurch and back to be 490 km and a single passenger produces 69 kg CO2, just under half the amount from driving. With respect to emissions, it is better to fly to Christchurch and back than it is to drive, unless you have two or more persons in the car or your car gets double the fuel efficiency (i.e., 5 litres per 100 km).
And then there are the emissions from food to consider. Information from USA has calculated the emissions in CO2e (CO2 equivalents, to account for other greenhouse gases, as well as CO2) per kilogram of consumed product. Keep in mind though that these numbers include processing, transport, cooking, wastage and disposal. Lamb tops the list, with 39 kg CO2e per kg consumed meat. Beef is somewhat lower at 27 kg per kg consumed. Mind you, these are US numbers, where beef and lamb are largely grain fed. Nearly 5 kg CO2e per kg consumed beef is due to feed production, which would be much less here, where most beef is grass fed. The emissions from lamb are higher than beef because less of the animal is used for food.
These numbers show that it doesn’t take many barbeques to match the emissions of a road trip to Christchurch and back. This example illustrates that cutting back on beef and lamb may go a long way to cutting a family’s greenhouse gas emissions. Pork (12 kg CO2e/kg consumed), chicken (7 kg CO2e/kg consumed) and eggs (5 kg CO2e/kg consumed) are lower emissions alternatives.
Cheese tops the dairy category, at 13.5 kg CO2e/kg consumed, with milk and yoghurt each around 2 kg CO2e/kg consumed. Surprisingly, most vegetables, nuts and legumes range from 3 kg CO2e/kg consumed (potatoes & rice) to 1 kg CO2e/kg consumed (tomatoes & lentils), largely due to wastage of fresh vegetables or the energy needed to cook potatoes, beans and lentils. A simple pressure cooker to cook beans and lentils will decrease emissions by decreasing cooking time. Propane for your hob produces around 3 kg CO2 per kg burned.
And of course, buying local can reduce the transport costs. A kg of fresh fruit airfreighted from California creates another 1.2 kg CO2e emissions.
What about waste? All organic material decomposes to CO2 and methane in municipal landfills, creating emissions. This includes paper (1042 kg CO2e/tonne), wood (828 kg CO2e/tonne) and mixed food & garden waste (587 kg CO2e/tonne). Composting can reduce the emissions from food scraps and garden waste by roughly 50%. We in Marlborough are lucky because the council flares (burns) the gas emitted by the Bluegums landfill, significantly reducing these emissions.
Hopefully, these values will have you thinking about how you could decrease your household’s emissions.
 The Environmental Working Group
At the Earth Day Party last April at A&P showgrounds, Richard and Madison queried, “The problem of climate change is overwhelming. What simple things can I do to make a difference?”
There are many sources of advice on how to cut greenhouse gas emissions and prepare for the changing climate ahead. Climate Karanga Marlborough suggests these to be the top seven for people living on the top of the South Island:
1. Try to cut your fossil fuel consumption. According to the latest Ministry for the Environment (MfE) inventory, carbon dioxide emissions from transportation and energy (electricity generation) made up 40% of New Zealand’s emissions in 2016. Electricity here on the South Island is almost entirely renewable, so electric power here creates minimal emissions. In order to cut fuel use, try driving less and carpooling if you can. If you haven’t used it, get to know your local public transport systems; it may be a good alternative to taking the car. Consider riding a push bike or an e-bike for local trips; it’s good for your health, saves emissions and it’s fun! Consider an electric car if your commute is suitable; and you will save significantly on fuel.
2. If you do need to drive a petrol car and fly, consider purchasing carbon offsets. These are certified programs in which you can purchase carbon dioxide uptake in forestry or other emissions saving projects to offset your emissions. Air New Zealand offers offsets for its flights. EKOS in Takaka and Enviro-mark Solutions of the US offer carbon offsets for a wide range of emissions.
3. Buy local goods and produce. Needless to say, there are fairly large emissions associated with international air and sea shipping. Buying local also helps your local economy.
4. Cut back on meat and dairy. It is an unfortunate fact for New Zealand that cattle, sheep and deer create methane in their digestive systems, which is a much more intense greenhouse gas than carbon dioxide. Fertiliser application and urine from cattle also create nitrous oxide emissions, which are an even more intense than methane and also help to destroy the ozone layer, increasing the risk of sunburn and skin cancer. According to the MfE, agriculture accounted for 49% of New Zealand’s emissions in 2016. While ongoing scientific research is looking for ways to reduce emissions from farming, cutting back on meat and dairy is a quick way to accomplish this in the meantime.
5. Look for opportunities to sequester (capture and store) carbon dioxide on your land and in your community. These might include tree planting and preservation, and farming practices designed to sequester carbon dioxide in soils, such as “regenerative” farming.
6. Get active. Encourage local councils, businesses, friends and relatives to cut emissions. Submit on the local and national government’s climate change action plans and legislation. There is only so much individuals can do in their personal lives to limit emissions. In order to be fair and effective, action to address climate change will need to be a coordinated and spread throughout our economy, in a national effort.
7. Participate in community preparedness. With wild weather expected in the years ahead, we’ll all need to know our neighbours and be ready when disaster strikes. New Zealanders are already pretty good at this already, thanks to earthquakes, but we’ll need to up our game. I was in Santa Rosa, California, during the firestorms of October 2017 that destroyed 5,300 homes. Neighbours knocking on doors in the middle of the night saved many lives.
One further recommendation is to calculate your family’s carbon footprint. The MfE website has a link to an ecological footprint calculator hosted by Global Footprint Network. Go to: “We all have a role to play”/”What you can do”. Unfortunately, the calculator doesn’t give you a breakdown of your individual emissions sources but you can discover this by running separate test cases (e.g., setting all activities to zero while testing one activity, such as air travel). Enviro-Mark Solutions offers a calculator with which you can purchase offsets.
The Blog posts are a collection of opinion articles written by CKM member Tom Powell for the Marlborough Express. Tom is a retired geologist who came to New Zealand in 2004 to work in the geothermal industry on the North Island, is a New Zealand citizen and now lives in Blenheim.