Humans cause climate changing

As this is the last round I will keep it exclusively for rebuttals: "My opponent wrote "during the last 2 BILLION YEARS the climate in the Earth has been fluctuating between..." It shows that climate was changing not in short time such as 2000 years, it was changing during 2 BILLION YEARS, which is very long period."The reason I said 2 Billion years was not because, over two billion years the climate has slowly gone from hot to cold, it was to demonstrate that the climate on earth is always changing. Over the past two billion years it has gone from cold to hot to cold to hot to cold to hot over and over again and as the chart I supplied last round demonstrates, it has been cooling for longer than it usually doe, Now it is warming up again and, being the self-centered, egotistic creatures that we are, we think that just because wea re around it has something to do with us. "It means that WEATHER conditions in the certain period of time IS CLIMATE. It proves that humans' affect to the weather can change the climate, as weather influences to the climate and they are not so different. That means my argument in the second round about how people change the weather is RELEVANT to the topic."What pro fails to realise is that the last part of the definition states: averaged over a series of years. So no, no matter how you put it, weather is not climate, weather is the day to day changes, whereas climate is the behaviour of the weather averaged over a series of years. If humans were to influence the weather over a long period of time that would be climate change. Changing one day of weather does not change the climate and hence is still not relevant to the debate. Also, while I can not dispute the facts that my opponent has supplied in the last round (for they are facts, I checked) I can attack they're relevance. For instance, constant reference to polar ice melting is made. I have already demonstrated how this is natural. For much of earths history there has been no ice at the poles what so ever, so to have such a substantial amount now is a rarity that will not last. He makes reference to the amount of CO2 in the water increasing. Again, I find this rather irrelevant, if the topic of the debate was 'Humans cause changes to ocean composition" it would. Basically, more CO2 in the ocean is not an example weather or climate. Pro also makes a lot of references to time frames, "Since 1950" or "for the last 100 years." The fact is that the temperature could have been slowly rising for the last 1000 years and we wouldn't know it. While human have always been able to feel the temperature, they have only recently started to record it. There were no monks that wrote what the weather was like everyday of the tear for their entire lives 1000 years ago. Basically, in order to say the climate has changed we need to be able to compare recent climate to past climates and since we do not have data on the climate every year for the past 1000 or so years, only a rough average like the rest of earths unrecorded history, we can not say, with any certainty, that the changes in the last 50-100 years have been special. Finally thank you to my opponent for an interesting and challenging debate! Let's hand it over to the voters...