Climate is a complex and chaotic system, there is variability on many scales, but we can discern climate change because of measurable trends on many different variables such as temperature, water cycle, sea level rise.
Changes will continue, we can make projections, which help us determine impacts, which help us set mitigation and adaptation policies.
Present: What do we know?
• Atmosphere is changing in composition, temperatures are rising, carbon dioxide is increasing, there are seasonal cycles, geographic variability
• These changes will continue and will be non-linear
• Indicators of warming: land surface temperature, sea surface temperature, sea level rise, troposphere temperature, ocean temperature, humidity, snow cover, Arctic sea ice, glacier mass
• Merging data sets with different properties can be hard but signals all show a warming earth, multiple lines of evidence, and growing consistency in data sets Climate Past
• Scientists have reconstructed atmospheric carbon dioxide composition using ice cores and sediment cores, which show our current increase in carbon dioxide is unprecedented
• Models show different trajectories for carbon dioxide and sea level rise
• It is still very hard to predict because we don’t fully understand all processes that go into the modeling, which bring us fact to our original point that climate is a complex, chaotic behavior.
Do Americans understand that climate change is occurring?
• Research shows that political orientation trump education when it comes to believing the science on climate change
o 25% of Americans don’t believe there is any evidence
o ‘97% of scientists believe climate change is happening’ isn’t a very effective message
o Motivated reasoning – education doesn’t fix the problem
• The likelihood of accepting scientific consensus:
o For Democrats, a college education increases the likelihood
o For Republicans, a college education decreases it
Science vs. Politics
• Science is how we mediate fact disputes
• Politics is how we mediate values disputes
• Scientific community can’t rely on only factual evidence to make the case, identity and values are the biggest driver of beliefs about climate change
• Scientific facts can inform but don’t dictate political outcomes
• Trying to mandate actions based solely on scientific outcomes leaves science advocates at a disadvantage in political debates
Important to remember…
• Focus on breaking connection between personal identity and factual beliefs
• Avoid spreading of misinformation
• Acknowledge when we don’t know something
• Understand the limits of scientific evidence in a political debate
• In focusing on people who have motives not to act on climate change – analyze what would work best to produce an outcome aligned with their expectations on the matter.