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Calstock, Tamar Valley In the woods, leaves obscure all but glimpses of the ebbing river

Dogwoods, covered in flowers with cream bracts, shine from the prevailing green of Cotehele’s valley garden and in the woods leaves obscure all but glimpses of the ebbing river.

Flag iris, water dropwort and reeds slow the flow of the Danescombe tributary into the Tamar and opposite this little delta, beyond the swirling current, two swans feed on the mud bank where “point stuff” – fallen leaves washed into the river – used to be shovelled into rowing boats for use as manure in the market gardens.

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Two very different storage technologies – one old, one new; one that takes years to build, one that can be built ‘within 100 days (or it’s free)’. How else do they differ, and is there a place for both?

Finkel says it clear investors prefer wind and solar because they are cheaper to build than traditional generation such as hydro and coal.

Turnbull's pursuit of "baseload dispatchable" power has all the hallmarks of the Trump administration's campaign against renewables. But data shows that countries with lots of wind and solar have better energy security.

AGL Energy Limited (AGL) today announced that the Board had appointed Graeme Hunt to succeed Jerry Maycock as Chairman following the AGM.

Major strategic partnership opens the possibility of integrating Vivid Technology and Honeywell products to create complete smart buildings solutions.

NNEF has just published its fourth annual New Energy Outlook with electricity’s future looking sunny — and windy, too — to the tune of trillions of dollars of new investment.

Sunny and windy Sunday afternoon in the U.K. sees carbon intensity power production level fall below 100g of CO2 per kWh for first time ever, gifting country’s energy market glimpse into future power generation mix.

AGL ridicules Coalition push for new "baseload" coal plants, saying that the only new "baseload" would be renewables, with gas or storage. "There’s a lot of misinformation out there," says CEO Andy Vesey.

Horizon Power’s stand-alone power project taking Fitzgerald River National Park off-grid with solar, battery storage and back-up diesel.

Queensland decides against proposed voluntary “buy out” of premium solar feed in tariffs in exchange for battery storage, but announces new rules to stop premium tariffs being rorted by batteries.

Falling technology costs and yet another hike in electricity prices are combining to make rooftop solar an economic no-brainer for most Australian households and businesses. Just ask Cory Bernardi.

Scientists crack the problem of why two-wheeled suitcases can rock from side-to-side and turn over.

AIIB will play highly influential role in Asia’s future development. On energy, this may include unlocking finance to catalyse a clean energy revolution.

South Korea move marks first major new international commitment away from coal since Trump pulled out of Paris climate agreement.

Electricity is just a symptom of the perils of populous governments. The only solution is to nationalise the lot.

Research suggests the existing networks of protected areas — national parks, marine parks and the like — won't go far enough to conserve the planet's biodiversity.

Once the coat around the seed is moistened, the embryo cells expand and burst out in a process called germination. shutterstock/NUM LPPHOTO

This is an article from Curious Kids, a new series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!

How can a tiny seed actually grow into a huge tree? – Finney, aged 6, from Bairnsdale in rural Victoria.

Tree seeds fall (like the tiny Eucalypt seeds) or helicopter down (like the winged seeds of the Maple) from their parents with a full set of instructions on how to grow.

A single tree may drop hundreds or even many thousands of seeds. Many of these seeds will become snacks for insects or fall where the ground is too hard, too dry, or just not suitable for trees. Some though will fall where the situation is just right!

Just right might mean bare dirt or some nice decayed mulch with enough sunlight.

The seed contains an embryo - a group of cells ready to form roots, a stem and the first leaves. Once the coat around the seed is moistened, the embryo cells expand and burst out in a process called germination.

Time-lapse of seed germination.

First, the roots will develop and push out and down into the soil to make sure the new plant can get water. Then the stem cells stretch up to display the first leaves.

The embryo uses food stored in the seed to power its initial growth until the leaves can start producing food. Small seeds don’t have much stored food so they have to fall in just the right spot to be successful. The parent tree has some ways to improve the chances of its seed finding the right spot, like dropping seeds after a bushfire has made the ground bare and free from other plants that would use all the water and nutrients.

For some plants, a bushfire triggers the release of seeds. Flickr/Tatters, CC BY

Once the roots are in the soil and the first leaves are in the sun, the plant is ready to really start growing.

People stop growing after they’ve become grown-ups but trees just keep getting taller and thicker however long they are alive.

Grass, bamboo and many other plants grow from the bottom up, so if you put a mark on the stem and come back in a little while, that mark will have been pushed further above the ground. But if you put a mark or even nail a board into a tree at one metre above the ground then come back in 10 years, it will still be only one metre above the ground. That’s because trees grow from the outside and the top up.

Some trees can grow to be more than 100 metres tall! Flickr/Andrew Malone, CC BY

The newest and outer shell of a tree contains all the living parts of the wood - the parts that move water up from the roots and food down from the leaves. If trees stop growing these outer, living shells of wood, the whole tree dies.

Some trees can grow to be more than 100 metres tall – that’s as tall as a skyscraper! In fact, humans are now building buildings out of wood that are over 50 metres tall and there are plans to go well beyond that.

The tallest tree currently is over 110 metres tall, and scientists think some trees may have been as much as 150 metres tall.

Trees grow from the top up.

A problem with getting even taller is that trees use water the same as you use blood - to move the nutrients and oxygen and other vital things around our body. But a tall tree has to move it from the roots to the tip of the leaves. For a 100 metre tall tree, that is like 30 flights of stairs. And a big tree could use more than 200 litres of water every day. Imagine carrying 30 buckets of water up 30 flights of stairs every day!

In our tall buildings, we need huge pumps and generators to move the water to the top, but trees just rely on their amazing structure and a little bit of power from the Sun.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. They can:

* Email your question to curiouskids@theconversation.edu.au
* Tell us on Twitter by tagging @ConversationEDU with the hashtag #curiouskids, or
* Tell us on Facebook

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Please tell us your name, age, and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Cris Brack does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.

Rising temperatures and southerly winds expected to bring toxic air to large parts of England and Wales on Wednesday

The mayor of London, Sadiq Khan, has triggered the capital’s emergency air quality alert as soaring temperatures combined with southerly winds are expected to bring dangerously toxic air to large parts of England and Wales on Wednesday.

The emergency alerts will see warnings displayed at bus stops, on road signs and on the underground.

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Senate inquiry starts as report into political, military and humanitarian risks of climate change across Asia Pacific released

As the Senate launches an inquiry into the national security ramifications of climate change, a new report has warned global warming will cause increasingly regular and severe humanitarian crises across the Asia-Pacific.

Disaster Alley, written by the Breakthrough Centre for Climate Restoration, forecasts climate change could potentially displace tens of millions from swamped cities, drive fragile states to failure, cause intractable political instability, and spark military conflict.

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