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A picture of the Earth, taken from space

Earth From Space

Cameras in space tell stories of life on our planet from a brand new perspective.

About the programme

Cameras in space tell stories of life on our planet from a brand new perspective, revealing new discoveries, incredible colours and patterns, and just how fast it is changing.

To find out more or to watch on iPlayer go to the BBC programme pages. 

Discover the range of qualifications and modules from the OU related to this programme:

New York from space

Copyright: NASA - CC0

Take a look at Earth's changes in more detail

Explore just what we can learn from looking at the Earth From Space. From melting ice floes, to the changing Himalayas.

Satellites reveal a dynamic Arctic under a changing climate

Earth is changing rapidly. Satellites play a crucial role in monitoring these changes. Dr. Kadmiel Maseyk explores what they have detected...

Watching the changes

Photo by Heather Shevlin on Unsplash

The Arctic is the fastest warming region on Earth, warming at twice the average rate of the rest of the planet.

Earth is going through widespread and rapid change, in our atmosphere, on land and in the oceans. An important theme in Earth from Space is the use of satellite data for the detection of change – our changing landscape, cities, glaciers and even the amount of plankton growing in our oceans. As the satellite record gets longer, and the information they collect gets more detailed, Earth observation data is providing increasingly valuable information on our changing planet.


Arctic in focus

Photo by Annie Spratt on Unsplash

One area of Earth that is changing dramatically, and where satellites have been critical for detecting these changes, is the Arctic. The Arctic is the fastest warming region on Earth, warming at twice the average rate of the rest of the planet. As it gets warmer, the extent of sea ice that covers the ocean in the polar north decreases. Satellites accurately map the seasonal fluctuations and long-term changes in sea ice, and these have shown that since 1980 the extent of sea ice at the height of northern summer has decreased by 2.5 million km2. 

This sea ice plays a crucial role in the climate of the region because sea ice has a high albedo, meaning it reflects a high proportion of the solar radiation that reaches the surface, keeping it cool. Open water is darker and absorbs more radiation, and therefore warms up more.  This loss of sea ice creates a positive feedback process, whereby the warmer ocean leads to less sea ice, which in turn leads to more open ocean absorbing more radiation and further warming of ocean surface. The decrease in ocean albedo contributes to a process known as Arctic amplification, and the rapid warming that is occurring in the region.


Grass and field from above

Photo by Sander Weeteling on Unsplash

Some areas are starting to show a slowing or even reversal of the greening trend, termed ‘browning’, indicating a decrease in plant growth or even vegetation dieback.

But it is not just the ocean that is changing in the Arctic. Over recent decades satellites have detected significant changes on land as well. Plants contain a pigment called chlorophyll, which gives them their green colour. Chlorophyll is responsible for absorbing the sunlight that drives the process of photosynthesis, ultimately providing the energy for life on Earth. We see plants as green because chlorophyll absorbs less green light than the red or blue parts of the spectrum, but overall plants absorb a lot and reflect much less in the visible part of the spectrum. In contrast, in the near infrared region they absorb less and reflect much more. Satellites exploit this difference in reflectance between the visible and near infrared regions to map the extent and amount of vegetation on Earth’s surface. This differential reflectance is captured in an index known as the Normalised Difference Vegetation Index (NDVI), and since the early 1970s satellites with the ability to separate these bands have been orbit, providing immensely valuable information on global vegetation dynamics.  Other surfaces, such as bare soil, do not show such a large difference in visible and near infrared reflectance, and areas with more vegetation have higher NDVI values.

Now that we have a few decades of such data, we can look for trends in the data – is it changing over time, and if so, how? Analyses over the Arctic region have revealed something dramatic. Reliable NDVI data is available from 1982 and this record shows a steady increase in the vegetation index across much of the Arctic tundra – those areas north of the tree-line where only shrubs and hardy low growing vegetation survives. Termed ‘Arctic greening’, this process is one of the most striking large-scale ecological changes seen in response to our changing climate. This trend indicates that there is more vegetation in these areas, that plant productivity is increasing. Surveys and studies on the ground confirm these ecosystems are undergoing rapid change. Vegetation is expanding into areas of bare ground and plants are getting taller and larger. But not all species respond in the same way. In particular, there is an increase in the proportion of shrub species, so the composition of the ecosystems is changing as well.


Photosynthetic Activity in US Midwest - Satellite photo

"Photosynthetic Activity in US Midwest" by NASA Goddard Photo and Video is licensed under CC BY 2.0

However, not all areas are greening, and in recent years another pattern has emerged in the NDVI data. Some areas are starting to show a slowing or even reversal of the greening trend, termed ‘browning’, indicating a decrease in plant growth or even vegetation dieback. The drivers for the browning are still being investigated, but reasons given include extreme climatic events (such as warming that induces melting followed by refreezing in winter), insect outbreaks, land surface degradation and fire. Overall, the picture is very complex, but it highlights the sensitive and dynamic nature of a region undergoing dramatic change.

Changes in ecosystem species composition are harder to detect by satellite than the amount of vegetation.  Hence there is a clear need for science on the ground to interpret and validate the details of the satellite signals, and to investigate the underlying processes at work. However, as the resolution of satellite imagery increases, we will be able to conduct more and more detailed science from space. While NDVI is the vegetation index with the longest record and therefore continues to be one of our most valuable, many more have subsequently been developed, taking advantage of reflectance properties across different parts of the spectrum to provide other information.

An important development in recent years has been the ability to detect a signal that is produced by plants during photosynthesis. When chlorophyll absorbs sunlight, a small amount of energy is released in the red region of the spectrum as a by-product of the energy capture process. Known as Solar Induced Fluorescence (SIF), this signal is closely linked to the rate of photosynthesis in the plants. SIF provides a new level of information, on actual photosynthetic activity rather than capacity, about our ecosystems. In 2023, the European Space Agency will launch it’s Earth Explorer Mission 8 – Fluorescence Explorer (FLEX). FLEX will be the first SIF-dedicated satellite, using a high-resolution imaging spectrometer to measure SIF across the globe and provide better insight into plant health and stress. This is just one example of the enormous advances being made in Earth observation that are helping us understand our rapidly changing planet.


A wide vista of the Himalayan mountain landscape

How to make a mountain: Crustal melting in the Himalaya

PhD student, Stacy Phillips, explains how researching granites in Eastern Bhutan can give clues about the evolution of the Himalayan mountain belt. 

These snow-capped peaks in north-western Bhutan now lie 6000m above the earth's surface, but they used to be 10's of km below the earth's surface.

Mountain belts represent areas of the earth’s crust that have been distorted by geological processes, been buried at depth and then brought back up to the surface. During this time the rocks are squeezed and deformed and sometimes melted at high temperatures and pressures. The presence of molten rock is important as it has a dramatic effect on the strength of the mountain belt, making it soft and weak and allowing the crust to move and almost ‘flow’ against the effect of gravity. Understanding how and when the rocks changed from being buried to being brought back to the surface is important for understanding how mountain belts evolve over time.


Dramatic topography in the Dangme Chu river valley, eastern Bhutan.

Dramatic topography in the Dangme Chu river valley, eastern Bhutan.

To investigate the processes that occurred in the heart of mountain belts, we can look at granite, the solidified remains of molten crust. My research involves looking at granites throughout the Himalaya, but particularly in Eastern Bhutan.


Granite lense close-up

Small-scale lenses of granite (white rock) formed from the melting of the surrounding schist (darker rock).

By looking at these rocks in the field, collecting samples and looking at them under a microscope, I can start to unravel how these rocks began to melt, and what reactions were occurring between minerals at the time. By carrying out chemical analyses of the rocks, involving techniques such as firing lasers at certain minerals, I can gain precise information about when the granites formed, some 30 to 40 million years ago. These analyses can also provide us with detailed information about the temperatures and pressures the rocks experienced. So by investigating the rocks at a very small scale I can then identify processes happening at a larger scale, and ultimately understand the dynamic evolution of the Himalayan mountain belt.


Meet the OU experts

Dr Julia Cooke, Lecturer in Ecology
Dr Julia CookeLecturer in Ecology - School of Environment, Earth & Ecosystem SciencesVIEW FULL PROFILE
Dr Julia Cooke, Lecturer in Ecology
Dr Julia CookeLecturer in Ecology - School of Environment, Earth & Ecosystem Sciences

Julia is a plant functional ecologist who uses plant traits, such as leaf longevity, plant height and maximum photosynthetic rate, as a powerful tool to describe plant ecological strategies. She has examined invasive species biology and how plants respond to climate change. Julia's work spans cellular to global patterns. 

Julia has taught courses on plant physiology, plant ecology and field studies, at Macquarie University, Sydney as well as an award-winning Masters level science communication course. At The Open University, she produces level 1 and 3 course materials.

Considering public engagement a critical part of being an academic, Julia is the author of a natural history picture book, has given public lectures, recorded postcasts and worked with school students to conduct an experiment that was later published in a peer-reviewed journal. Last year she was a presenter for Soapbox Science which seeks to bring science to a broader audience while increasing the visibility of women in science.

Dr Kadmiel Maseyk, Lecturer in Environmental Science
Dr Kadmiel MaseykLecturer in Environmental Science - School of Environment, Earth & Ecosystem SciencesVIEW FULL PROFILE
Dr Kadmiel Maseyk, Lecturer in Environmental Science
Dr Kadmiel MaseykLecturer in Environmental Science - School of Environment, Earth & Ecosystem Sciences

Kadmiel's research involves understanding ecosystem response to the environmental changes of the anthropocene, through linking plant processes with ecosystem function, particularly in the area of carbon and water cycling. He has worked in polar, boreal, mid-latitude and tropical regions.

Kadmiel produces and presents for level one Questions in Science, level two Environmental Science, and level three Ecosystems modules. This includes teaching on the changing Arctic, which focuses on how we are using space-based information to understand this rapidly changing region plus Kadmiel is developing material that introduces students to the critical role that space-based information plays for monitoring and investigating ecosystem processes.

Dr Clare Warren, Senior Lecturer
Professor Clare WarrenProfessor of Metamorphic Geology - School of Environment, Earth & Ecosystem SciencesVIEW FULL PROFILE
Dr Clare Warren, Senior Lecturer
Professor Clare WarrenProfessor of Metamorphic Geology - School of Environment, Earth & Ecosystem Sciences

Clare is a Senior Lecturer in the School of Environment, Earth and Ecosystem Sciences. She is a geologist with specific interest in mountains and geological timescales. Clare researches the forming of mountains and tries to determine how quickly all these different processes happen, and also where and when, to build a 3D picture of how the mountain belt formed.

Clare teaches on the Masters dissertation module, and also on a couple of undergraduate modules where she focuses on metamorphic geology (the rocks that transformed under heat and pressure) and also on geological time and timescales. Clare has made a number of  short videos documenting fieldwork.  She has also given a number of public lectures about her work.

Stacy Phillips, Research Student
Stacy PhillipsResearch Student - School of Environment, Earth & Ecosystem SciencesVIEW FULL PROFILE
Stacy Phillips, Research Student
Stacy PhillipsResearch Student - School of Environment, Earth & Ecosystem Sciences

Stacy is a PhD researcher in the School of Earth, Environment and Ecosystems Sciences, and works with the Dynamic Earth research group. Her PhD research title is "When did crustal melting form the soft centre at the heart of the Himalaya?"

She is passionate about science communication and has produced a number of short videos explaining her research to a general audience. She also helped create a podcast to share her love of geology and fieldwork with others and is the co-host and website designer for the Fieldwork Diaries podcast , a podcast talking to researchers about their fieldwork experiences.

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