will have led to an increase in greenhouse gas emissions.

And I think that that's quite a powerful thought.

But it does have the potential to make us feel guilty

when we think about decisions we might have made

or quite simply the lifestyles that we lead and enjoy.

But we can also turn that thought on its head,

and think that if we've had such a profound

but a negative impact on our climate already,

then we have an opportunity to influence the amount of future climate change

We can either choose to start to take climate change seriously,

and significantly cut and mitigate our greenhouse gas emissions,

and then we will have to adapt to less of the climate change impacts in future.

Alternatively, we can continue to really ignore the climate change problem.

to adapt to very much more powerful climate impacts in future.

As people who live in countries with high per capita emissions,

we're making that choice on behalf of others as well.

our government negotiators and policymakers have been coming together

and they've been focused on avoiding a two-degree centigrade warming

That's the temperature that's associated with dangerous impacts

So two degrees centigrade constitutes dangerous climate change.

But dangerous climate change can be subjective.

So if we think about an extreme weather event

that might happen in some part of the world,

and if that happens in a part of the world where there is good infrastructure,

where there are people that are well-insured and so on,

But if that exact same weather event happens in a part of the world

or they're not having good support networks,

then that same climate change impact could be devastating.

It could cause a significant loss of home,

but it could also cause significant amounts of death.

So this is a graph of the CO2 emissions at the left-hand side

and time from before the Industrial Revolution

And what's immediately striking about this

is that emissions have been growing exponentially.

If we focus in on a shorter period of time from 1950,

the Intergovernmental Panel on Climate Change,

then rolling on a few years, in 2009 we had the Copenhagen Accord,

where it established avoiding a two-degree temperature rise

in keeping with the science and on the basis of equity.

And then in 2012, we had the Rio+20 event.

And all the way through, during all of these meetings

And if we focus on our historical emission trend in recent years,

and we put that together with our understanding

of the direction of travel in our global economy,

for a four-degree centigrade global warming

than we are for the two-degree centigrade.

and think about this four-degree global average temperature.

Most of our planet is actually made up of the sea.

Now, because the sea has a greater thermal inertia than the land,

the average temperatures over land are actually going to be higher

The second thing is that we as human beings don't experience

rainy days, especially if you live in Manchester like me.

It's the hottest day that you've ever experienced.

there's concrete and glass all around you.

but it's six, eight, maybe 10 to 12 degrees warmer

That's the kind of thing we're going to experience

under a four-degree global average temperature scenario.

but also the extremes in terms of storms and other climate impacts,

【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。