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Climate Change

Climate Change – what’s it all about?

Climate vs Weather

Climate is the how our planet's atmosphere behaves over long periods of time, defined as greater than 30 years. Weather is the way the atmosphere is behaving over short periods ranging from minutes to months.

Climate Change

Climate Change is a natural phenomenon that has occurred throughout the Earth’s history. The Climate is constantly changing due to: variations in the sun’s energy; changes in reflectivity of the earth’s surface and atmosphere; and changes in the greenhouse effect.

Greenhouse Effect

The greenhouse effect is the process whereby the earth’s surface is warmed by radiation from its atmosphere. It is influenced by both natural events (like volcanic eruptions) and through the activities of mankind.

Greenhouse Gases

Earth is warm enough to sustain life because gases in the planet’s atmosphere hold heat. These gases are called greenhouse gases because they act just like a greenhouse by trapping heat inside the planet’s atmosphere, making the average temperature on Earth 15 degrees Celsius. Humans have increased the amount of greenhouse gases in the atmosphere by about 35 percent. The more greenhouse gases in the atmosphere, the warmer the average temperature gets.

Main Greenhouse Gases

The two major greenhouse gases both occur naturally and can be increased due to human activity.

  • Carbon dioxide (CO2): Responsible for 63 percent of global warming over time, and 91 percent in the last 5 years. This gas is produced from burning fossil fuels, such as coal and oil. It also occurs naturally as it flows in a cycle between oceans, soil, plants and animals.
  • Methane (CH4): Responsible for 19 percent of global warming, this gas is produced by rotting garbage and wastewater, gas from livestock, and rice crops. Swamps and anything that decomposes without air naturally creates methane.

Human activity sources of greenhouse gases – humans add to greenhouse gases by:

  • Energy Use: through burning fossil fuels which release around three quarters of the human-produced greenhouse gases into the atmosphere. Half of the fossil fuels are burned to create electricity and heat and the balance is created through manufacturing and transportation.
  • Land use: removal of forests and land use changes create about a quarter of human-produced greenhouse gases. Trees absorb carbon dioxide from the atmosphere so clearing forested land for agriculture means more carbon dioxide stays in the air.

Man vs Nature

Human emissions are estimated to be only 3% of total emissions but the main worry is the human emissions are increasing at a faster rate than in the past and this could cause problems for certain populations in the future. Natural events cannot be controlled but human impact on the planet can be.

Human influence on the climate is assessed as being mainly through pollution and the burning of fossil fuels which release carbon into the atmosphere. Many scientists believe carbon release is the most problematical and has the biggest impact. Reducing carbon release globally requires buy-in from every nation but it also comes with an economic cost as replacements for fossil fuels such as coal and oil are currently more expensive to utilise and not as efficient.

Climate change may well lead to changed global and localised weather patterns with an increase in extreme weather events and increase in sea levels. This would see changes in land utilisation where some areas may not be able to grow the same crops they would previously and large-scale population movements. It may result in an economic benefit to some areas and an economic cost to others. Human relocation occurs as people move away from low-lying areas, such as Bangladesh, or from areas that become more arid.

Trees are Good

Trees have the ability to absorb CO2 from the atmosphere and store it within the tree and this process is called carbon sequestration. A forest then acts like a storage room for absorbed Carbon. More trees means more absorbed Carbon to offset against the emissions and increasing forested land is one of Trees That Count’s objectives.  

What is the World doing?

The UN has agreed that the world needs to try to limit global warming to within 2°C above pre-industrial levels. Beyond that level, scientists say the impacts of climate change will become far more dangerous and severe. The problem is, countries haven’t agreed to cut their carbon emissions on anything like the scale needed to achieve that goal. On current trends, scientists predict warming of more than 4°C this century with extreme heatwaves, floods, species extinctions and even conflicts forecast as a result.

Why is Greenhouse Gas Reduction so hard to achieve?

The world is overwhelmingly reliant on burning fossil fuels to provide energy for heat, power and transport resulting in an estimated more than 50 gigatonnes of greenhouse gas emissions each year, as of 2010. That number keeps rising as emerging economies grow. To stay within 2°C it needs to fall to around 41 gigatonnes by 2030 and even effectively zero by the end of the century. That entails a complete transformation of the world’s energy system, which isn't easy to achieve; cheap to undertake; or even technologically possible in a short timeframe. There is also the major question of what is fair to a nation and how its general competitiveness in goods production will be effected.

Let’s be Fair

The main reason why international agreement on greenhouse gas reduction is hard to obtain is due to the question of fairness. Most countries don’t want to pledge to unilaterally reduce emissions unless they feel others are doing their fair share too. For poorer countries, burning more fossil fuels (increasing emissions) remains the cheapest route to the kind of development rich countries, like NZ, enjoy. If they are to switch to expensive green energy, they argue that rich countries must help them pay for it. All this needs to be resolved before a global deal can be agreed.

NZ & Climate Change Round 1 (Kyoto)

NZ implemented the Climate Change Response Act 2002 to create a legal framework to ratify the Kyoto Protocol and meet its obligations under the United Nations Framework Convention on Climate Change. The Act also created the Emissions Trading Scheme (ETS) as the major tool to help reduce emissions. The objective of the ETS is to put a price on greenhouse gases which creates an incentive to reduce emissions and increase tree planting.

Paris 2015

The 21st UN sponsored international meeting on Climate Change was held in Paris in December 2015 with the intention of reaching a legally binding (and universal) agreement. This was a first since the 1997 Kyoto Protocol where 37 countries agreed to be bound by greenhouse gas reduction targets.

NZ’s Position

NZ produces around 80% of its energy needs from renewable electricity which is a much larger percentage than most countries, so there is limited ability to greatly reduce “dirty” energy consumption. However, NZ also has a much higher proportion of its total production (or GDP) in the high greenhouse gas emitting food industry. The NZ Government’s stance is there aren’t yet cost-effective technologies to reduce emissions in the agricultural sector. One of NZ’s main objective, or contribution, is to increase the planting of trees and ensuring they remain as forest rather than change land use after harvest.

Worst Emitters by Country

China is the world’s largest emitter with roughly one quarter of world’s total. Next is USA (20%); EU (13%); India (6%); Russia (6%); and Japan (4%). NZ’s emissions are guesstimated at 0.09%, so no matter what we do our contribution to the global reduction is insignificant and almost too small to measure.    

NZ Targets for Paris

The New Zealand Government announced post-2020 climate change target is to reduce greenhouse gas emissions to 30 per cent below 2005 levels by 2030. The targets are:

  • a provisional post-2020 target of 30 per cent below 2005 greenhouse gas emissions levels by 2030;
  • an unconditional target of five per cent below 1990 greenhouse gas emissions levels by 2020;
  • a long-term target of 50 per cent below 1990 greenhouse gas emissions levels by 2050; and
  • a conditional target range of 10 to 20 per cent below 1990 greenhouse gas emissions levels by 2020, if there is a comprehensive global agreement.

New Zealand's targets were ratified in September 2016.  


NZ’s main tool to incentivise emission reduction is the Emission Trading Scheme (ETS). Putting a price on carbon gives economic signals to the marketplace with the aim of incentivising the planting and maintenance of tree plantations and adding a cost to polluters. Certain sectors are required to acquire and surrender emission units to account for their direct greenhouse gas emissions or the emissions associated with their products.The ETS was formed and introduced in 2008 and is currently being reviewed.  

How can individuals help reduce emissions?

The main way individuals can contribute is to reduce their own energy consumption and look at alternatives. House insulation is one of the easiest ways to reduce consumption in the house but it also comes down to using only what you need. Alternative power sources like solar panels and wind turbines may be possible in certain areas but try “travelling smart” by walking, cycling, carpooling etc. One of the negatives for New Zealanders is the production of 1 kg of meat uses 10 times more energy than making a kg of beans or grains.