The importance of sustainability

The focus of sustainability is ensuring that the world operates in equilibrium (i.e. that the 5 capitals are balanced). These individual capitals interact with each other so that too much of this capital isn't used up. 

However, consider that: 

• 2016 was the warmest year on record globally, with an anomaly of 0.77°C above the long-term average (see the UK Met Office).
• According to the World Meteorological Organization, 13 of the 14 warmest years of the past 135 years have occurred in the 21st century.  
• CO2 emissions in the developed world have fallen by around 29% since 1990 (falling in the UK by 9.7% in 2014). Total UK greenhouse gas emissions are currently 36% below 1990 levels, while emissions from developing countries have been rising. Yet provisional figures from the Netherlands Environmental Assessment Agency for 2016 and the International Energy Agency are encouraging, with global emissions of CO2 rising by 0.7% in 2014 and no change in 2015 and 2016. This is the result of less coal burning and greater use of renewable energy resources, with emissions falling in more developed countries plus China, demonstrating that changes in policies and positive action can make a difference. The largest fall came in the US, caused by a drive away from coal to shale gas supplies and renewable power.
• The Arctic sea ice has shrunk in every successive decade since 1979, with 1.07 million km² of ice loss every decade. 
• 20% of the Amazon rainforest has been cut down in the last 40 years, more than that lost in the previous 450 years. 
• By the end of this century global temperatures are predicted to rise by more than 1.5°C compared to 1850– 1900 levels with 1.02°C already having occurred globally by the end of 2015, a rise of 0.15°C in just 3 years.
• CO2 emissions in the developed world have fallen by around 29% since 1990 (falling in the UK by 9.7% in 2014). Total UK greenhouse gas emissions are currently 36% below 1990 levels, while emissions from developing countries have been rising. Yet provisional figures from the International Energy Agency suggest that global CO2 emissions stalled in 2014 – it will be interesting to see, however, if this is a blip or the start of a genuine reversal.
• CO2 levels in the atmosphere have been increasing as despite the emissions stabilising in the last 3 years we are still emitting 35bn tonnes of CO2 each year. There is no consensus on what CO2 level the world's ecology can cope with, although optimistic views on the concentration ranges from 400–500 parts per million (ppm), the latter put forward by Sir David King, then the government's chief scientific advisor (2000–2007). The EU meanwhile has set a target of 550ppm, the lowest in the world. The CO2 level has so far risen from pre-industrial revolution levels of 280ppm to its current level of 430ppm according to Stern Report, although others have it at 403ppm as of September 2017 (CO2 Earth).

There is now very much a scientific consensus that global warming is occurring. There is only minimal dissent that this is not as a result of human activities, with the biggest dissenters of the past (China and Australia) now very much behind the drive to reduce future CO2 emissions. The one major exception at the moment is the US under President Donald Trump, which is stating it will pull out of the Paris climate accord, increase coal production (and therefore burning) and row back on a number of environmental initiatives (although individual states, cities and corporations are not following the presidential lead). See also isurv Climate change: adaptation and mitigation.

There is a continued belief in the majority of the developed world that while green initiatives may add short term costs to business and consumers, they can help to provide an area for growth and job creation. The Green Alliance reported in their 2012 publication Green Economy: A UK Success Story that the green economy in the UK was worth £122bn, or almost 10% of economic activity. So, an extra burden, an area of growth and jobs, or a necessity in order to keep our planet suitable for life?