human activities

• human activities increase the amounts of greenhouse gases in the atmosphere, which means that the temp rises and more energy from the sun is trapped

  • carbon dioxide
  • methane
• 
  

  human activities include:

  • burning fossil fuels
  • deforestation
  • agriculture
• burning fossil fuels increases co2

  • coal = electricity
  • petrol and diesel to power cars
  • gas to heat homes
• deforestation:

  usually to provide land for grazing cattle

  • normally co2 is absorbed by growing trees
  • however, this releases large amounts of co2 as well as decreasing the amount absorbed by photosynthesis
• agriculture: releases methane

  • cattle, cows, pass wind
  • growing rice in paddy fields
• 
  

  effects of global climate change:

  • rising sea leaves as polar ice sheets and glaciers melt = more flooding in low lying areas
  • more severe weather, e.g. storms
  • change the distribution of animals such as insects
  • change the distribution of insect-borne diseases i.e. malaria
• peer review is the process of detecting false claims, e.g. based on poor evidence of bias
• many scientists believe that human activity will cause the temperature of the earth's atmosphere to increase at the surface which will result in global climate change

  this is based on peer review: evidence is shared between different scientists who can criticise the evidence and decide if its valid
• however, it is difficult to model as climate change is complex

  this leads to simplified models/speculation/opinions based on parts of evidence that could be bias in the media

  = scientists must work harder to communicate the ideas to general public
• uncertainties in the evidence base:

  • cannot predicts with certainty how much the temperature of the atmosphere will increase
• renewable sources of methane:

  • animal waste
  • food in landfill