Humans and Sea Level Change Over the Last 11,000 Years

What about the most recent period of sea level change (i.e., during the Holocene) since humans have been involved?

Once again, given the Hansen data (Figure 4.24), the time period for most significant human impact on climate is shown within the last few 1000 years. Major human industrial activities became prominent only within the last few centuries, but human influences on the natural environment go back 1000s of years. As we discussed previously, ice core, sediments, tree rings, coral growth patterns, and other proxy data sets have proven to be great resources for exploring recent and more historic climate change in time scales of just seasons to several hundred thousand years. Ice layers are especially revealing. Given that we know that glacial ice builds a layer every season, glacial ice layers trap the chemical signatures of the atmosphere and record any of the major global events that happened in that year (i.e., use of new chemicals by humans, volcanic eruptions, large scale fires, etc.). This provides glaciologists and other climate scientists an excellent record to evaluate how climate changes on an increment-by-increment, or layer-by-layer basis. In addition, instrumental measurements have further added to our ability to measure temperatures as well as sea level positions. Careful evaluation of these data sets, in comparison to proxy data sets have allowed scientists the ability to produce a robust conciliatory record that helps us understand more explicitly the ways in which human or anthropogenic activity is contributing to the changes we are now measuring and experiencing.

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Figure 4.24 (repeated): This diagram shows sea level position for the last five million years since the end of the Miocene and the beginning of the Pliocene. Sea level is established here using an "albedo proxy" to establish sea levels.
Credit: Root Routledge, created from source information and graphs from James Hansen publications. Copyright Root Routledge, but available for non-commercial distribution