What types of measurements indicate that climate change is occurring?

We can definitely measure the climate changes when change occurs in the temperature. This winter has been horrific and seeing the temperature drop drastically is definitely a sign of the climate change. More snow and precipitation is seen. Water levels rise. I live right near a river and the ice buildup caused flooding in the nearby neighborhoods where some residents needed to evacuate. In the spring, pollen counts rise which can indicate climate change. Droughts can occur which is an obvious climate change.

How were these measurements collected?

Technology has definitely progressed and collecting measurements in climate change is easier to record. Above just observation, satellites can collect data along with instruments like weather balloons. Comparing old data records can help us see the changes over time by comparing and analyzing data.

What are some of the challenges associated with collecting data over large periods of time (i.e., hundreds of years)?

Since technology wasn't as advanced as it is now, data collected over the years may not be as detailed and we can get now. Theories have been created and it’s not possible to go back in time to reevaluate what was written for that time. Scientists were limited in what they could test as compared to today’s abilities.

How has technology enhanced our ability to collect the data necessary to understand climate change?

Since the equipment is updated that allows us to collect data and read it, the findings are more accurate than they were years ago.

What additional data would be useful?

Being able to check the pollution levels in air samples could be helpful.

What are the risks associated with waiting for more data as well as reacting to incomplete data?

If we waited to get more data, the data could expire because of climate changes while we are waiting. For instance, if we are waiting and measuring the levels of water and ice accumulated during such a time, the ice could melt which would then affect the outcome of our data. Therefore, we wouldn't have accurate data.