When we deny the poor and the vulnerable their own human dignity and capacity for freedom and choice, it becomes self-denial. It becomes a denial of both our collective and individual dignity, at all levels of society.
As human beings, we are vulnerable to confusing the unprecedented with the improbable. In our everyday experience, if something has never happened before, we are generally safe in assuming it is not going to happen in the future, but the exceptions can kill you and climate change is one of those exceptions.
Once we start deliberately messing with the climate systems, we could inadvertently shift rainfall patterns (climate models have shown that rainfall in the Amazon might be particularly vulnerable), causing collapse of ecosystems, drought, famine, and more.
Whether it's watching a $4,000 laptop fall off the conveyor belt at airport security, contending with a software conflict that corrupted your file management system, or begging your family to stop opening those virus-carrying 'greeting cards' attached to emails, all computer owners are highly leveraged and highly vulnerable technology investors.
We worry about appearing awkward in a presentation. But up to a point, most people seem to feel more comfortable with less-than-perfect speaking abilities. It makes the speaker more human - and more vulnerable, meaning he is less likely to attack our decisions or beliefs.