climate is a very complicated subject that thousands of scientists from many different fields are studying it people looking at the modern atmosphere people looking at them or ocean people looking at the modern water cycle land as well as people studying historical and what we call paleoclimate or ability oceanography records in lakes oceans and ice cores as well and these studies of ancient climates are of critical importance because they help establish the basic boundary conditions of the natural system so we can understand better how much what's going on today actually deviates from natural cycles because it most assuredly does we need to understand why there are people who are focusing on the physics of the system people focusing on the chemistry or the biology all of which can be recorded in the geology that is the marine sediment or the ice cores on planet earth physics is important because the atmosphere in the ocean circulate in the exchange gas carbon dioxide levels chemistry biology is involved primarily through photosynthesis which is the process by which plants cooling plants in the ocean take atmospheric carbon dioxide and turned into oxygen just like the green wanted your house plants the ocean circulates that's physics and that's also driving the exchange of carbon dioxide between the atmosphere of the ocean in essence my job involves looking at  there are times i can't believe that that's actually what i do as i look at mud and what we all call mud is actually what we call marine sediment and marine sediment is a very complicated mixture of basically everything that is happening in the ocean and in the atmosphere at any one point in time there's atmospheric dust that's being blown around that's called aeolian input named after the greek god in that consists of essentially dirt from the land very very fine grained millions of a metre in size of being blown out of the ocean and possibly there is also microscopic plankton that float in the ocean and when they die or they get eaten their body parts and they were can it matter falls down to the sea floor and lives there well there's also direct organic matter which is not just fish remains and things like that but it's more than organic carbon associated with those planes there's also minerals that grow on or in the sea floor over millions of years of time so the sediment itself that looks just like mud is very complicated mixture of geological materials biological materials and chemical materials as well and what we study when we look at these cores is we look at for example the abundance of plankton at one time or another in earth's history or the abundance of those wind blown aeolian deposits at other times and we look to see if say for example during windy or times you know an earth which might be recorded by grains of a larger grain size minerals of a larger grain size or if the earth is wetter we might have that different mineral compositions and we see how or if those changes in the mineral structure or are they only in material that correlate with changes in the biology of the system so we can really look at the linkages the bio geochemistry of the system trying to link atmospheric processes to ocean processes to geological processes and what's wonderful about marine sediment is if we go to some areas where the sedimentation rate is very slow it is the sediments piling up on the sea floor very slowly as in maybe a millimeter every thousand years with one core of maybe ten twenty thirty or forty meters we can look way back into geological time millions of years back in the geological time and by examining the fine grained layers we can study these different processes on the other hand we go to areas where the sedimentation rate is fast on the order of maybe a centimeter a year something like that then we can look at very highly resolved very fine rapid changes in earth's climate and looking at places with different sedimentation rates we can use the marine sediment as a tape recorder of ocean atmosphere history there's a lot of different aspects to studying climate and the complexities are what make it such a challenge for us to understand but just like the human body is very complicated we understand quite a lot about the human body but there are some things we don't understand and so we're pursuing other ways of other means of looking at climate as well the work i've been doing recently for example focuses on the asian monsoon system which stretches from centrally northern china and japan all the way down through southeast asia indonesia and into india and collectively the asian monsoon system which most people think of this high rainfall time periods during and during the year yearly cycle but the asian monsoon delivers water to over half of the world's population east asian monsoon which is the focus of a oceanographic research cruise that i participated on it helped lead last year feeds about a third of the world in there what we're studying is we're studying how changes in the jet stream coming across asia may move north or move south as a function of climate so perhaps during glacial time periods or non glacial time periods the jet stream may be more northerly or more southerly or more strong or more weak and in all those scenarios that it delivers different amounts of water to asia to china and japan particularly so understanding the natural behavior of that asian month soon system over the last millions of years as well as the last hour isn't yours really helps us understand what's going on now and although my own work doesn't do this it will help us predict the future or at least put some constraints on what the future will hold as our earth continues to warm the monsoon is a good example of the physics of the system how atmospheric circulation will move north or south across asia and deliver different amounts of dust to the ocean and we can then look at the records of that dust to help us figure out the position of that jet stream that i just spoke about another aspect over different time scales that people are looking at in both the biology sometimes that dust that blows out into the ocean for example part of it will dissolve in the surface ocean in release iron iron is you know as a nutrient we need it all life forms me iron the addition of iron into the surface ocean is likely to stimulate biological productivity that is you add a higher into the system and the plant plankton grow how much more they grow remains to be determined people are studied in the long term effect of adding iron naturally into the ocean is also being studied some of the work i've done with colleagues over time periods of a million years in the open ocean equatorial pacific pretty clearly shows that the addition of natural iron will cause biological between the addition of iron into the system and more biological productivity and that's interesting because it's thought that during glacial time periods when the earth is drier there's more dust being blown around in the atmosphere if there's more dust being blown around in the atmosphere there's more iron being released into the surface ocean when that dust lands and lands in the ocean and then when there's more iron then you have more biological productivity and more biological productivity you might draw down atmospheric c o two a little bit which makes the earth a little colder a bit inverse global warming so we've seen that in the natural system if you add iron or some other nutrients you have the potential to change the concentration of atmospheric carbon dioxide which is of course related to global temperatures some people have suggested that perhaps mankind should and should synthetically and clear into the surface ocean as a way to combat global warming and we're nowhere near understanding the system enough to engage in manipulation of earth's natural system to that extent it's very premature to think of that because it's a very very complicated system and we might end up causing more in obtaining the cores themselves from the deep ocean floor to very challenging engineering task and there are many brilliant engineers who come up with very creative ways to retrieve this material from the sea floor and ha back up one of the ships were able to study it on the research ships themselves we do a lot of measurements that are of parameters that are transitory that will decay away very rapidly unless we do them for example some people and this is some of the work that i do we look at the pour water that is the water that's contained between the grains of the sediment because the chemistry of that water tells us a lot about the nature of that core material and in some ways what the temperature was at the time of that material was the positive temperature of the ocean or other things that we other scientists do as we look at the color of each individual layer of the color because as it turns out color can be measured in very very small intervals and the color will correspond to the different types and national government repositories all over the world that have been gathered fifty sixty even seventy years ago and these core materials are very very valuable and people still work on them i've got samples in my lab of cores that were taken from before i was born that we're studying and still learning new information from people work on the chemistry that we're going there ology they work on virtually every aspect you can to get a complete understanding of the different processes that resulted in that material being deposited and then correlating that time so we can look at changes of history because climate is a consists of incredible diverse array of international participants on my last trip for example people from china korea japan germany italy england u zealand australia they have forgotten a country or two from which i for which i apologise i'm leaving next week on another research trip with a completely different set of scientists people from the united states germany japan canada and england so people all over the world are interested in this and it's very interesting to me because i've been doing this since i was a graduate student to learn the different perspectives because different countries do science in very different ways some countries are more top down management driven some countries like the us are more grass roots and bubble up with individual scientists dr genda but it takes all these different approaches to address the complexities of the system and also it takes the large government support to actually do science because taking a ship out to sea is quite costly studying the pores is quite costly keeping the cores around for several decades so for example people thirty years from now will use analytical techniques that haven't even been invented yet to learn more about the scores and climate in the past it's crucial so it takes a diverse group of scientists if they're completely different cultural approaches to studying the science and it takes a fair bit of financial support to do it as well what i find most thrilling about the study of the old ocean atmosphere as it's recorded in the inside is the simple fact that what we're looking at is how the complexities of this planet operate and how climate has ferried to certain degree how the ocean is  very to a certain degree that's part of the natural system it's very clear in the theory experiment and observation that the earth is warming we don't understand all the processes behind it but it's very very clear the earth is warming and the fast consensus of scientists understand this we also understand the basics of the system carbon dioxide tension of carbon dioxide in the atmosphere change heat and so on and so forth that  people understand and we're working with having said that however we don't understand everything about the system and i think what's very exciting news some of the work that i'm doing and my colleagues a it's putting very good boundaries in the complexities of the natural system and so we can figure out back before we started adding carbon dioxide to the atmosphere at the great rate that we're doing  ice cores and records like that you really have to understand how cold it could possibly get in the past how warm it could possibly get in the past what the rates of change were how long lived these cold episodes were or warm episodes were so we can better understand the system are in now better understand what it may be for our children and grandchildren