30 Jul 2019

Let's push back Earth Overshoot Day

Posted in: Household action

Let’s push back Earth Overshoot Day

For most people Monday 29 July will probably seem like any other day. But in terms of measuring the human impact on our planet it is probably the most important date on the 2019 calendar.

You see, 29 July is Earth Overshoot Day - the date when our human population’s demand for natural resources and services exceeds what our planet can regenerate in a year. Considering we’re just over halfway through the year, it starkly illustrates the unsustainable nature of the way we use the Earth’s resources and create waste.

Independent think tank Global Footprint Network calculates Earth Overshoot Day, by measuring the number of days each year that Earth’s biological capacity provides for the ecological footprint of the human population.


Unfortunately, every year it has been calculated the date has been brought forward. In 1970, it was all the way back at 29 December. By 2000 it was 23 September. Ten years ago it was 18 August. The pattern is crystal clear that each year we are using more and more of Earth’s resources, and more quickly!

Delving a little bit deeper, we can analyse the specific overshoot days for each country.  From a New Zealand perspective, it doesn’t make for great reading. Our national overshoot day is 6 May, nearly three months earlier than the planet as a whole. In fact, there are only 21 countries that have an overshoot day earlier in the year than we do.

The ecological footprint of the average New Zealander is around 4.8 global hectares, while the global biocapacity sits at only 1.63 global hectares per person. So, if the whole world lived like Kiwis do, humanity would need almost three Earths to sustainably look after us all. That’s a pretty sobering statistic!

The Global Footprint Network wants to move Earth Overshoot Day back by five days per year, meaning that sustainable use of the Earth’s resources would be reached by 2050. The good news is they share plenty of ideas the global community can do to help reach this goal:

  • Unsurprisingly, the big-ticket item is to tackle humanity’s ever-increasing carbon emissions. Reducing the carbon component of our ecological footprint by 50 per cent would move us from consuming the resources of 1.7 Earths down to 1.2 Earths. This alone corresponds to moving the date of Overshoot Day by a whopping 93 days – all the way to the end of October!
  • The increase in personal mobility has been a critical driver of economic and social change over the last hundred or so years. But, if we improve transport-related issues, such as through the rollout of modern technologies, improved public transport, walking and cycling, and better urban planning, we can reduce the amount of driving people do by 50 per cent. This would push back Earth Overshoot Day by 11.5 days.
  • If we drive greater use of current energy efficient commercial technologies for buildings, industrial processes, and make full use of the existing decarbonisation opportunities for electricity generation, we can move back by at least 21 days.
  • Halving global meat consumption and replacing it with a calorie-equivalent vegetarian diet would push Earth Overshoot Day out another 15 days, while simply cutting food waste in half would gain us a further 10 days. Reforesting 350 million hectares of forest, typically used for agricultural production, would improve things another 8 days. It takes 14 times more productive land to produce one tonne of beef as it takes to produce one tonne of grain – so even moderate reductions in meat consumption will make a difference.
  • Continuing to empower women and girls through better access to education results in greater gender equality and is proven to increased family planning and lower reproduction rates. This can have a major effect on the amount of human pressure on the planet. If every second family was a child smaller by 2050 the world’s population would reduce by around a billion people, pushing Earth Overshoot Day out by another 30 days.

The Ecological Footprint Calculator where you can work out your own ecological footprint and your own individual Earth Overshoot Day is available at https://www.footprintcalculator.org/. It is a fantastically simple, albeit revealing, way to measure your ecological impact. It is also a great tool to encourage us to take meaningful action and measure our progress towards creating a more sustainable and ecologically-sympathetic community.